c语言案例源程序

C程序设计源程序（内部资料）主编:刘云二〇一三年十月第一部分简单C程序1.1.1显示一行文字产显示一行文字“WelcometoeWorld!”的程序・/#include<stdio.h>main()(prinは”WelcometoCWorld!\n',);}1.1.2两个整数求和/・计算并显示两整数之和的程序・/#include<stdio.h>main(){inta,b,sum;/・变量声明・/printf(?,Inputfirstinteger 显示提示信,息・/scanfC'%d",&a);/*读取ー个整数・/printfflnputsecondinteger\ガ’);/・显示提示信息・/scanf("％d”,&b);/*读取ー个整数字/sum=a+b;/・两数相カロ*/printf("Sumis%d'n”,sum);/*显示两数之和*/return〇;/・返回〇表示程序成功地结束*/)1.2.1算术运算#include<stdio.h>main()(printf("\nLI:40%%7二％d”,40%7);printf("\nL2:40%7=%d”,40%7);printfCu\nL3:3.O/-4.O+1,6*2.O/5,O=%f\3.0/-4.0+1.6*2,0/5.0);printf(t4\nL4:2/3*l000=%dM,2/3*1000);printf("\nL5：2/3*1000=％ド,2/3*1000);printf('ヘnL6:2/3*1000二%e“，2/3*1000);printf("\nL7:2.0/3*1000二％ド,2.0/3*1000);printf("\nL8:2f/3*1000二％ド,2173*1000);printf(l<\nL9:Sizeof3is%dM,sizeof(3));printf(uu\nL10:Sizeof3.0is%d”,sizeof(3.0));)1.2.2赋值运算#include<stdio.h>main()Iintk,x,y;k=5;x=k++;/*后缀运算,先把k的值赋给x,然后k的值加1*/printf("\nLl:k=%d,x=%d”,k,x);k=5;y=++k;/・前缀运算,先使k的值加1,然后将k的值赋给y*/printf('\nL2:k=%d,y=%d”,k,y);x=y=5;printf(，z\nL3:--xis%d,y--is%d”,--x,y一);k=x=y=5;k=++x-++y;printf(，z\nL4:%d,%d,%d”,k,x,y);k=++x+y++;printf("\nL5:%d,%d,%d”,k,x,y);k=x一+-y;printf(zz\nL6:%d,%d,%d”,k,x,y);kニーx+++y;printf('\nL7:%d,%d,%d，z,k,x,y);x=y=5;printf("\nL8:x+=x-=x*xis%d〃,x+=x-=x*x);printf(〃、nL9:y+=y-=y*二yis%dzz,y+=y-=y*=y)；}3printf中输出表列求值#include<stdio.h>voidmain(){inti=8;printf(z%d,%d,%d,%d,%d\n〃,++i,--i,i--，i++,-i--);}4交换两个变量的值#include<stdio.h>main(){inta,b,tem;printf("Inputintegeraandb\n’')；scanfC'%d,%d",&a,&b);tem=a;a=b;b=tem;printf(,,a=%d,b=%d\n,,,a,b);)5四舍五入#include<stdio.h>#include<math.h>main(){doublea,b;printf(MInputreala\nM);scanf("%lf\&a);b=noor(a*100+0.5)/100;printf(Hb=%.2f\nH,b);}第二部分分支程序设计2.1.1求绝对值#inchide"stdio.h"main(){intx,y;scanf("%d",&x);y=x；if(x<0)y=-x;printf(66x=%d,lxl=%d\n,,,x,y);}1.2显示三数中的奇数main()(intx,y,z;printf(uinputx,y,z:");scanf(a%dy%d,%d”,&x,&y,&z);if(x%2)printf(u%disoddnumber!\nv,x);if(y%2)printf("%disoddnumber!\n,y);if(z%2)printf("%disoddnumber!\nn,z);2.1.3三数中取极值main()(inta,b,c,max,min;printf("inputa,b,c：v;scanf("%d,%d,%d"，&a,&b,&c);max=a;if(b>max)max=b;if(c>max)max=c;printf("themaximumis:%d\nx,,max);min=a;if(min>b)min=b;if(min>c)min=c;printf("theminimumis:%d\nM,min);2.2.1两数的比较#include”stdio.h"main()(intx,y;printf("inputx,y:");scanf("%d,%d”,&x,&y);if(x>y)printf("themaximumis:%dn,x);elseprintf("themaximumis:%d”,y);}2.2.2判定一数能否被另ー数整除main()printf("inputx,y:“)；scanf("％d,%d"，&x,&y);if(x%y)printf(“NO”)；elseprintf("YES");}3.1分段函数求解main(){intx,y;scanf("％d"，&x);if(x>=0)if(x>0)y=x+l;elsey=x;elsey=x-l;printf("x二%d,y二％d\n"，x,y);}2.3.2一元二次方程求解#includenmath.hHmain(){floata,b,c,d,a2,xl,x2;printf(r,Inputa,b,c\n")；scanf(”%f,%f,%f”,&a,&b,&c);if(a==0)/米解一元一次方程・/(xl="c/b;printf("root=%f\n”,x1);/*输出一次方程根・/}else/・解一元二次方程・/{d=b求b-4*a*c;a2=2*a;xl=-b/a2;if(d>=0)(x2=sqrt(d)/a2;printf(Mrealroot:\n");/・输出实根・/printf(,,rootl=%f,root2=%f\n',,xl+x2,xl-x2);)else(x2=sqrt(-d)/a2;printf(Hcomplexroot:\n");/*输出复根・/printf(,,rootl=%f+%fi\nM,xl,x2);printf("root2=%f-%fi\n',,xl,x2);3.3闰年判断问题①、普通年能被4整除且不能被100整除的为闰年。②、世纪年能被400整除的是闰年③、对于数值很大的年份,这年如果能整除3200,并且能整除172800则是闰年。如!72800年是闰年,86400年不是闰年#include**stdio.hMmain(){intyear,leap=0;/*leap=0:预置为非闰年・/printf("Pleaseinputtheyear:");scanf("%d",&year);if(year%100!=0){if(year%4==0)leap=1;}else{if(year%400==0)leap=1;}if(leap)printf("%disaleapyear.\n",year);elseprintf("%disnotaleapyear.\n",year);)3.4显示学生成绩与等级main()(intx;printf("pleaseinputx(0<=x<=l(X)):^^);scanf("％d”,&x);if(x>100llx<0)printf(Mx=%ddataerror!\n",x);elseif(x>=90)printfC4x=%disgradeA!\n",x);elseif(x>=80)printf(<<x=%disgradeB!\n",x);elseif(x>=60)printfC4x=%disgradeC!\n",x);elseprintf(<<x=%disgradeD!\n",x);}}第三部分循环程序设计1.1累加和程序1:应用for循环设计/*for循环求s=l*2+2*3+…99*10〇・/main(){longi,s;s=0;for(i=l;i<=99;i++)/・设置循环i=l,2,•••,99*/s+=i*(i+D;/*把通项i*(i+l)累加到s中・/printf(〃l*2+2*3+…+99*100=%ld\n”,s);)程序2:应用while循环设计/*while循环求s=1*2+2*3+-,,+99*100*/main(){longi,s;i=l;s=0;while(i<=99)/*设置循环i=l,2,…，99*/{s+=i*(i+l);i++;}/・把通项i*(i+l)累加到s中・/printf("l*2+2*3+…+99*100或Id\n",s);}程序3:应用dowhile循环设计/*dowhile循环求s=l*2+2*3+…+99*10〇・/main(){longi,s;i=l;s=0;do{s+=i*(i+l)；i++；}/・把通项i*(i+l)累加到s中・/while(i<=99);/*设置循环i=l,2,•,,,99*/printfCl*2+2*3+―+99*100=%ld\n",s);}1.2代数和/・求s=l-l/2+l/3-l/4+--l/100*/main(){intk,n;floats=0;for(k=l;k<=100;k++)if(k%2=l)s+=1.0/k;/・应用分支实现符号一正一负・/elses-=l.0/k;printf(，zs=%9.6f”,s);}求C语言编程,e=l+l/l!+1/2!+l/3!+...+l/n!,精确度le-6#includeくstdio.h>mainOintn,k;floate;n=l;e=0;k=l;while(n<le-6)(e+=n;n=n/(k+l);)printf("e=%f\n”,e);1.3递归算法（求阶乘、最大公约数）/・循环累乘求阶乘n!*/main(){inti,n;longt;scanf("%d",&n);t=l;/・积变量t赋初值1*/for(i=l;i<=n;i++)t=t*i;/・循环变量i累乘到t,体现阶乘运算・/printf(/z%d!=%ld\nz\n,t);)/・递归求阶乘N!*/floatfac(n)intn;{longf;if(nニニ〇)f二1;/・初始条件・/elsef二n*fac(nT);/・递归关系・/return(f);)main(){intn;longy;printf("inputn:");scanf1%d”,&n);y=fac(n);printf(*%d!=%ld\n*,n,y);}递归算法(求阶乘、最大公约数)【例】用递归调用函数编写计算f(n)=n!的程序。longfact(intn)Iif(n<0)printf(un<0,dataerror!M);elseif(n=0||n二l)return1;elsereturn(n*fact(n-l));}main(){intn;longintp;printf("inputn:");scanf("%d",&n);p二fact(n);printf("%d!=%ld\n",n,p); )1百鸡问题钱买百鸡，，鸡翁一,值钱五,鸡母ー,值钱三,鸡雏三,值钱ー,百钱买百鸡,问翁、母、雏各几何?你的任务是求解下面这个问题。问题是这样描述的:a文钱可买ー只公鸡,b文钱可买ー只母鸡,c文钱可买d只小鸡。用m文钱买n只鸡,那么有公鸡x只、母鸡y只、小鸡z只。求解出符合题意的x,y,z。设母鸡X只,公鸡Y只,小鸡100-X-Y只,所以5Y+3X+(100-X-Y)/3=100且X,Y为整数，所以可以得出正确答案，有三种情况:.公鸡4只,母鸡18只,小鸡78只.公鸡8只,母鸡11只,小鸡81只.公鸡12只,母鸡4只，小鸡84只main(){intx,y,z;for(x=l;x<=19;x++)for(y=l;y〈=33;y++)for(z=l;z<=100;z++)if(z%3==0&&x+y+z==100&&5*x+3*y+z/3==100)printf(*x=%d,y=%d,z=%d\n”,x,y,z);/・同时满足时打印*/)3.2.2解Pel!方程/・解PELL方程:x'2-ny'2=l.*/^include<math.h>main(){intn,m,t;longa,x,y;printf("解PELL方程:x'2-ny"2=l.\n*)：printf("请输入非平方正整数n:");scanf("%d",&n);m=sqrt(n);if(m*m==n){printf("n为平方数,方程无正整数解!、n");return;}printf("解PELL方程:x-2-%dy-2=l\n",n);for(y=1;y<=10000;y++)/・实施穷举,约定10000内・/{a=n*y*y;x=sqrt(a+l);if(x*x==a+l){printf("方程的基本解为:つ;printf("x=%ld,y=%ld\n”,x,y);break;}3.3.I穷举法编程计算100至999之间有多少个数,其各位数字之和是5。例如:122、131是满足要求的数的两个例子。main(){inti,j,k,m,count=0;for(m=100;m<=999;m++)(i=m/100; /・分离每一位数・/j=(m-i*100)/10;k=m-i*100-j*10;if(i+j+k=5) /・注意:等于运算符为“二"(两个等号)*/count++;)printfcount);}3.3.2累加求和求Sn=a+aa+aaa+-+aa-a(n个a)之值,其中a是一个数字。例如:2+22+222+2222+22222(此时n=5),n由键盘输入。Main(){inta,n,i,sn=0,tn;scanf("%d,%d",&a,&n);tn=a;for(i=l;i<=n;i++)(sn=sn+tn;tn=tn*10+a;printf("%d\n",sn);3.3.3质因数分解/・质因数分解乘积形式・/ttinclude^math.h"main(){longintb,i,k,m,n,w=0;printf(*[m,n]中整数分解质因数.\n");printf("请输入m,n:");scanf(z/%ld,%ld/z,&m,&n);for(i=m;i<=n;i++)/*i为待分解的整数・/{printf("%ld="，i);b=i;k=2;while(k<=sqrt(i))/*k为试商因数・/{if(b%k==O){b=b/k;if(b>l){printf("%ld*",k);continue;}/*k为质因数,返回・/if(b==l)printf("%ld\n",k);}k++;}if(b>l&&b<i)printf("%ld\n",b);/・输出大于i平方根的因数・/if(b==i){printf("(素数!)、n");w++;}/*b=i,表示i无质因数・/}printf("其中共%d个素数.\n",w);3.4.1最大公约与最小公倍数main(){longinta,b,r,k;scanf("%ld,%ld",&a,&b);k=a*b;r=a%b;while(r>0){a=b;b=r;r=a%b;}/・实施辗转相除・/printf("最大公约数为:%ld\nzz,b);printf("最小公倍数为:%ld\n",k/b);3.4.2水仙花数水仙花数是指ー个「位数(n23),它的每个位上的数字的n次幕之和等于它本身。(例如:「3+5c3+3A3=153)main(){inti,j,k,n;for(n=100;n<1000;n++){i=n/100;j=(n/10)%10;k=n%10;/・分离n各位数字i,j,k*/if(n==i*i*i+j*j*j+k*k*k)/・检验是否符合条件・/printf(〃％d",n);})4.3完全数完全数(Perfectnumber),又称完美数或完备数,是ー些特殊的自然数。它所有的真因子(即除了自身以外的约数)的和(即因子留数),恰好等于它本身。ttinclude"math,h”mainO{intb,i,k,m,n,c[100];longa,s,x,y,d[100];printf(“求区间[x,y]中的完全数.");printf("请输入整数x,y:");scanf("%ld,%ld",&x,&y);printf("[%ld,%ld]中的完全数有:、n",x,y);for(a=x;a<=y;a++){s=l;n=0;b=sqrt(a);for(k=2;k<=b;k++)/・试商寻求a的因数k*/if(a%k==0){s=s+k+a/k;n++;c[n]=k;d[n]=a/k;}/*a/k也是a的因数・/if(a==b*b){s=s-b;m=n-l;}/・若a=ビ2,去掉ー个b重复因数*/elsem=n;if(a==s){printf("%ld=l",a);/・分两段从小到大打印因数之和・/for(i=l;i<=n;i++)printf("+%d",c[i]);for(i=m;i>=l;i--)printf("+%ld",d[i]);if(a%2==l)printf("奇完全数!")；printf("\n");}})3.4.4勾股数所谓勾股数,一般是指能够构成直角三角形三条边的三个正整数(a,b,c)。

BPa2+b2=c2,a,b,cGN/・勾股数组・/#include"math,h”main(){longa,b,x,y,z,d,n二〇;scanf(<4%ld,%ldM,&a,&b);printf("在国ld,%ld］范围内,寻求勾股数组:\n")；for(x=a;x<=b-2;x++)/・设xくyくz,循环判别*/for(y=x+l;y<=b-l;y++){d=x*x+y*y;z=sqrt(d);if(d==z*z&&z<=b){n++;printf(u%ld,%ld,%ld\nM,x,y,z);})printf("共有％Id组勾股数。"，n);}3.5.1金字塔main(){intn,k,m;printf(“请输入金字塔的行数n：つ;scanf("%d",&n);for(k=l;k<=n;k++)/・控制循环n次,打印n行・/{for(m=l;m<=50-k;m++)printf(*%c*,32);/・每行先打印50-k个空格・/for(m=l;m<=2*k-l;m++)printf("枇”,42);/・接着打印2k-1个"*"*/printf("\n");})5.2空心菱形#includeくmath.h>main(){intd,e,n,k,m;printf("请输入菱形的行数n(奇数):〃);scanfC%d*,&n);d=(n+l)/2;for(k=l;kく=n;k++)/・控制循环n次,打印n行・/{e=fabs(k-d);/・菱形上下对称,应用fabs(k-d)函数,求浮点x的绝对值・/for(m=1;m<=e+45;m++)printf("%c”,32);/*打印每行前面空格・/printf("%c”,42);/*打印每行的前一个星号・/if(e<d-l){for(m=l;m<=2*(d-e)-3;m++)printfC%c",32);/*打印中间空格・/printf('%c',42);}/・打印中间各行的后一个星号・/printf(*\n*);}第4部分数组程序设计1.1Fibonacci数列在数学上,斐波纳契数列以如下被以递归的方法定义:F0=0,Fl=l,Fn=F(n-l)+F(n-2)(n>=2,n《N*)/"Fibonacci数列递推求解・/main(){intk,n;longs,f[50];printf("求数列的第n项与前n项和,请输入n:");scanf(*%d*,&n);f[l]=l；f[2]=l;s=2;/・数组元素与和变量赋初值・/for(k=3;k<=n;k++){f[k]=f[k-l]+f[k-2];/・实施递推*/s+=f[k];}/・实施求和・/printfCF数列第%d项为:%ld\n〃,n,f[n]);printf("F数前%d项之和为:%ld\n”,n,s);)1.2复杂递推数列/*2x+3y递推程序・/main(){intm,n,t,k,i,h,j,w,a[30000];printf(,\ninputm:");scanf("%d",&m);a[1]=1;a[2]=2;t=2;n=0;for(k=2;kく=m;k++){for(i=l;i<=k-l;i++){w=2*a[k]+3*a[i];if(w<=m&&a[k]!=a[i])a[++t]=w;/・判断w是否为递推项・/w=2*a[i]+3*a[k];if(w<=m&&a[k]!=a[i])a[++t]=w;}}/・判断w是否为递推项・/for(j=l;j<=m;j++){for(k=l;k<=t;k++)if(a[k]==j){n++;printf(*%4d(%3d)”,j,n);break;}}printf("\nn=%d",n);4.2.1矩阵的处理(生成矩阵、交换和基本运算)【例】将一个二维数组行和列元素互换,存到另一个二维数组中。ftinclude<stdio.h>main()(inta[2][3]={{1,2,3},{4,5,6}};intb[3][2],i,j;printf("arraya:\n,z);for(i=0;i<=l;i++){for(j=O;j<=2;j++){printf("%5d",a[i][j]);b[J][i]=a[i][j];}printf("\n");}printf(warrayb:\n'z);for(i=0;i<=2；i++)(for(j=0;j<=l;j++)printf("%5dzz,b[i][j]);printf(zz\nH);}}【例】求・个3*3矩阵对角线元素之和程序分析:利用双重for循环控制输入二维数组,再将a[i][i]累加后输出。#include<stdio.h>main()floata[3][3],sum=0;intij;printf("pleaseinputrectangleelement:\n");for(i=0;i<3;i++)for(j=0;j<3;j++)scanf("％俨,&a[i皿);for(i=0;i<3;i++)sum=sum+a[i][i];printf("duijiaoxianheis%6.2f"/sum);【例】有一个3义4的矩阵,要求编程序求出其中值最大的那个元素的值,以及其所在的行号和列号。include<stdio.h>voidmain()(inti,j,row=0,colum=0,max;inta[3][4]={{1,2,3,4},{9,8,7,6},{-10,10,-5,2}};max=a[〇][0];for(i=0;i<=2;i++)for(j=0;j<=3;j++)if(a[i][j]>max){max=a[i][j];row=i;colum=j;)printf(，fmax=%d,row=%d,colum二％d\n,

max,row,colum);}4.3.1数制转换/・十进制整数转换为P进制*/main(){longn;intc,m,k,p,s[100];charr[16];r[10]=K;r[ll]=B1;r[12]=C;r[13]= ;r[14]=E*;r[15]=FJ;m二〇;printf("\n请输入十进制数n:;scanf&n);printf(*\n请输入转换数制p(2-16)0;scanf&p);printfC(%ld)10=C,n);while(n!=0){c=n%p;n=n/p;m++;s[m]=c;}/・实施除P取余・/for(k=m;k>=l;k-)/・从后往前逐位打印输出・/if(s[k]>9)printf(*%c*,r[s[k]]);/*超过9时打印相应字母*/elseprintf(*%d*,s[k]);printf(")%d\n”,p);/・十进制小数转换为P进制・/main(){floatn;intc,m,k,p,t,s[100];charr[16];r[10]='A';r[ll]二'B';r[12]='C';r[13]=,D';r[14]='E';r[15]='F';m=0;printf("Xn请输入十进制纯小数n:");scanf("%f",&n);printf("\n请输入转换数制p(2T6);scanf&p);printf("\n请输入最多转换的位数t:");scanf("%d",&t);printfC(%f)10=(0.n);while(n!=0&&m<t){n=n*p;c=n;n=n-c;m++;s[m]=c;}/・实施乘P取整・/for(k=l;k<=m;k++)/・从前往后逐位打印输出・/if(s[k]>9)printf(*%c*,r[s[k]]);/*每一位超过9时打印相应字母*/elseprintf(*%d*,s[k]);printf(')%d\n”,p);)4.3.2二分法一般地,对于函数f(x),如果存在实数C,当x=c是f(c)=0,那么把x=c叫做函数f(x)的零点。解方程即要求f(x)的所有零点。先找到a、b,使f(a),f(b)异号,说明在区间(a,b)内一定有零点,然后求f[(a+b)/2],现在假设f(a)く〇,f(b)>0,aくb如果f[(a+b)/2]二〇,该点就是零点,如果f[(a+b)/2]く〇,则在区间((a+b)/2,b)内有零点,按上述方法在求该区间中点的函数值,这样就可以不断接近零点如果f[(a+b)/2]>0,同上。通过每次把f(x)的零点所在小区间收缩一半的方法,使区间的两个端点逐步迫近函数的零点,以求得零点的近似值,这种方法叫做二分法。用二分法求下面方程在(T0,10)之间的根。2x3-4x2+3x-6=0#include<math.h>main(){floatxO,xl,x2,fxO,fxl,fx2;doprintf(wEnterxl&x2:");scanfド％f,%f",&xl,&x2);fxl=xl*((2*xl-4)*xl+3)-6;fx2=x2*((2*x2-4)*x2+3)-6;)while(fxl*fx2>0);do{x0=(xl+x2)/2;fx0=x0*((2*x0-4)*x0+3)-6;if((fxO*fxl)<O){x2=x0;fx2=fxO;}else{xl=xO;fxl=fxO;}}while(fabs(fx0)>=le-5);printf(Hx=%6.2f\n",xO);)3.3圆周率n的高精度计算/・高精度计算圆周率れ*/ttinclude"math.h〃main(){floats;intb,x,n,c,i,j,d,1,a[5000];printf("\n输入精确位数:")；scanf("%d",&x);for(s=0,n=l;n<=5000;n++)/・累加确定计算的项数・/{s=s+log((2*n+l)/n);if(s/log(10)>x)break;}for(i=0;i<=x+l;i-H-)a[i]=0;for(c=l,j=n;j>=l;j-)/・按公式分步计算・/{d=2*j+l;for(i=0;iく=x;i++){a[i]=c/d;c=(c*d)*10+a[i+l];}a[x+l]=c/d;for(b=0,i=x+l;i>=0;i—){a[i]=a[i]*j+b;b=a[i]/10;a[i]=a[i]%10;)a[0]=a[0]+1;c=a[0];)for(b=0,i=x+l;i>=0;i—){a[i]=a[i]*2+b;b=a[i]/10;a[i]=a[i]%10;}printf(*\npi=%d.*,a[0]);/・遂位输出计算结果・/for(1=10,i=l;i<=x;i++){printfa[i]);1++;if(l%10—0)printf「ッ;if(l%50==0)printf("\n");}}1排序算法(选择法排序、冒泡法)【例】任意输入n个数,按由小到大的顺序排列并显示输出。(选择法排序)选择排序的思想:将数组中第一个元素的值与其后的所有元素的值进行比较,如果前者大于后者就互换,这样将所有元素中最小值就放在第一个元素中。依次类推,直到最后一个元素为止。#include<stdio.h>^definen5 /・对5个数按升序排列main()(inta[n],i,j,t;printf(input5number'n");for(i=0;i<n-l;i++)for(j=i+l;j<n;j++)if(a[i]>a[j]){t=a[j];a[j]=a[i];a[i]=t;)【例】冒泡法排序(升序)基本思想:(将相邻两个数比较，小的调到前头)1)有n个数(存放在数组a(n)中),第一趟将每相邻两个数比较,小的调到前头,经n-1次两两相邻比较后，最大的数已“沉底”，放在最后ー个位置,小数上升“浮起”；2)第二趟对余下的n-1个数(最大的数已“沉底”)按上法比较,经n-2次两两相邻比较后得次大的数;3)依次类推,n个数共进行n-1趟比较,在第j趟中要进行n-j次两两比较。#include<stdio.h>#definen10 /・对10个数按升序排列main()(inta[n],i,j,t;printf("input10numbers\n");for(i=l;i<n;i++)scanf("%d",&a);printf("\n");for(j=l;j<=9;j++)/*外循环9次for(i=l;i<10-j;i++)/・内循环if(a[i]>a[i+l]){t=a;a=a(i+l];a[i+l]=t;}printf("thesortednumbers:\n")；for(i=l;i<=10;i++)printf("%dnH,a[i]);}【例】将一个数组逆序输出。(用第一个与最后一个交换。)#include<stdio.h>#definen5main(){inta[n]={9,6,5,4,1},i,temp;printf(zz\noriginalarray:\n*);for(i=0;iprintf("%4d",a[i]);for(i=0;i{temp=a[i];a[i]=a[n-i-l];a[n-i-l]=temp;}printf(zz\nsortedarray:\n");for(i=0;iprintf("%4d",a[i]);4.4.2査找算法(顺序査找、折半査找、统计、求和、计数)顺序査找查找是在程序设计中最常用到的算法之一,假定要从n个整数中查找x的值是否存在,最原始的办法是从头到尾逐个查找,这种查找的方法称为顺序查找。【例】从键盘上任意输入五个不同的整数存入a数组中,查找关键字x是否在数组a中。#include<stdio.h>#definen5main()(inta[n];intx,i;for(i=0;i<n;i++)scanf(”%d”,&a[i]);printf(“输入査找关键字x:");scanf("%d",&x);for(i=0;i<n;i++)if(x==a(i])break;if(i<n)printf("关键字在数组中,其位置是:％d\n〃,i+l);elseprintf(〃关键字％d不在数组中、n〃,x);)【例】折半查找法:输入六个有序(升序)的整数存放在a数组中,查找关键字x是否在数组a中。基本思想：先用“中间元素”与关键字比较,若相等,则找到;若关键字的值大于“中间元素”的值,则用右半部分的“中间元素”再与关键字比较;否则,用左半部分的“中间元素”再与关键字比较。#include<stdio.h>#definen7main()(inta[n];intx,しhigh,low,mid;for(i=0;i<n;i++)scanf("%d",&a[i]);printf("输入査找关键字x:");scanf("％d”,&x);low=0;high=6while(low<=high){mid=(low+high)/2;if(x<a[mid])high=mid-l;elseif(x>a[mid])low=mid+l;elsebresk;)if((low<=high))printf(〃关键字在数组中的位置是:％d\nウmid);elseprintf("关键字％d不在数组中'n”,x);}分析过程:a[0] a[l] a[2] a[3] a[4] a[5] a[6]20 30 35 45 50 60 70low=0 mid=(low+high)/2high=64.4.3有序数列的插入、删除操作(字符串的插入删除也类似)把ー个整数按大小顺序插入已排好序的数组中。为了把ー个数按大小插入已排好序的数组中,应首先确定排序是从大到小还是从小到大进行的。设排序是从大到小进序的,则可把欲插入的数与数组中各数逐个比较，当找到第一个比插入数小的元素1时，该元素之前即为插入位置。然后从数组最后ー个元素开始到该元素为止,逐个后移ー个单元。最后把插入数赋予元素i即可。如果被插入数比所有的元素值都小则插入最后位置。【例】将无序数从大到小排列#include<stdio.h>main()|inti,j,p,q,s,n/a[ll]={127,3,6,28,54,68,87,105,162,18);for(i=0;i<10;i++){p=i;q=a[i];for(j=i+l;j<10;j++)if(q<a[j]){p=j;q=a[j];}if(p!=i){s=a川;a[i]=a[p];a[p]=s;}printf("%d",a[i]);|printf("\ninputnumberin'')；scanf("%d",&n);for(i=0;i<10;i++)if(n>a[i])for(s=9;s>=i;s—)a[s+l]=a[s];break;}a[i]=n;for(i=0;i<=10;i++)printf("%d",a[i]);printf("\n");}【例】在ー个有序的数列中找到ー个数并且删除它。#include<stdio.h>main(){inta[7]={0,l,2,3,5,6},i,k,j;for(k=0;k<6;k++)printf("%d",a[k]);printf("\nH);printf("Pleaseinputthenumbertodelete:H);scanf(”%d”,&i);for(k=0;k<6;k++){if(i==a[k])(for(j=k;j<5;j++)a[j]=a[j+l];break;})if(k==6)printf('*Thenumbernotfound");printf("Thesortedis:\n");for(k=O;k<5;k++)printf("%d"戸[k]);getch();}第五部分函数程序设计5.1.1求X#include"stdio.h"doublepow(doublex,intn)/・函数的定义在main。之前时不需要声明・/{doubley;inti;y=l;if(n==0)}return1.0;elseif(n>0){for(i=l;i<=n;i++)y=y*x;returny;)else{for(i=l;i<=-n;i++)y=y*x;return1/y;)main()(intx,y;printf(*inputx:");scanf &x);printf(*inputn:");scanf &y);printf("result:%f\n”,pow(x,y));5.1.2万年历^include<stdio.h>main()(inti,j,day,year,temp,tempi;longintYeardays：)longintsumdays(intyear);/・函数定义在main()之后,在main()中要声明・/intIsLeapYear(intyear);/・函数声明的格式和定义函数时的头ー样・/intmonth_day[]={0,31,28,31,30,31,30,31,31,30,31,30,31,29},everyday[6][14];/・此数组用来保存计算所得的日历・/printf("Pleaseentertheyear:");scanf("%d",&year);Year_days=sumdays(year);/・调用函数sumdays()计算天数,year是实在参数・/for(temp=l;temp<=6;temp++) /・分6次输出12个月的日历・/(for(i=0;i<6;i++)for(j=0;j<14;j++)everyday[i][j]=0;switch(temp)/・一行输出二个月份・/case1:printf(zz\tJanuary%d\t\tFebruary%d\n,year,year);break;case2:printf(*\tMarch %d\t\tApril %d\n*,year,year);break;case3:printf(*\tMay%d\t\tJune%d\n/z,year,year);break;case4:printf(*\tjuly%d\t\tAugust%d\n*,year,year);break;case5:printf〈\tSeptember%d\t\tOctober%d\n,year,year);break;case6:printf(*\tNovember%d\t\tDecember%d\n*,year,year);break;printf("MonTueWedThuFriSatSunMonTueWedThuFriSatSun\n");i=j=0；for(temp_i=0;temp_i<(Year_days%7);temp_i++)/・初始化数组・/everyday[0][j++]=0;day=1;while(dayく=month_day[2*tempT]) /・把奇数月的日历输入数组・/(if(j%7==0)j=0,i++；everyday[i][j++]=day;Yeardays++;day++;i=。,j=7;for(temp_i=0;temp_i<(Yeardays%7);tempi++)/・初始化数组・/everyday[0][j++]=0;day=l;if(IsLeapYear(year)&&2*temp==2)/・调用函数判断是否是闰年・/while(day<=month_day[13]) /・把闰年偶数月的日历输入数组*/|if(j%14==0)j=7,i++;everyday[i][j++]=day;Year_days++;day++;}elsewhile(day<=month_day[2*temp])/・把偶数月的日历输入数组・/if(j%14==0)j=7,i++;everyday[i][j++]=day;Year_days++;day++;}for(i=0;i<6;i++) /・输出存储在数组中的日期・/(for(j=0;j<14;j++){if(everyday[i][j]!=0)printf("%-4d”,everyday[i][j]);elseprintfC");if(j=6)printf(*つ;}printf('\n");}if(getch()=-q)exit(0);)getchO;)intIsLeapYear(intyear)/・定义函数IsLeapYear()用来判断是否是闰年・/{if((year%4==0)&&(year%100!=0)||(year%400=0))return1;elsereturn0;}longintsumdays(intyear)/・定义函数sumdays()计算输入年份之前的天数・/(intyearstart=l,leapsum=0;while(year_start<year){if(IsLeapYear(year_start))/・调用函数IsLeapYear()判断是否是闰年・/leapsum++;year_start++;return366*leapsum+365*(year-leapsum);5.2.1求最小值#include<stdio.h>main(){intx,y,z,min;intmintwo(int,int),minthree(int,int,int);printf(*\nPleaseinputthreeintergers:*);scanf(*%d%d%d”,&x,&y,&z);min=minthree(x,y,z); /・函数调用,传入三个实参・/printfCMinis%d”,min);getchO;}intmintwo(inta,intb)/・函数定义・/(return(a<b?a:b); /・使用条件语句,并将计算结果返回*/}intminthree(inta,intb,intc)(intz;}z=mintwo(a,b); /・函数内嵌套调用函数mintwoO*/z=mintwo(z,c);return(z);5.2.2奇偶函数调用#include<stdio.h>main()(floateven(),odd(),deal1(); /・声明需调用的函数・/floatsum;intn;printf(*\nPleaseinputainterger:*);while(1) /・判断用户输入的数据是否大于1*/scanf(*%d*,&n);if(n>l)break;)sum=(n%2==0)?deal1(even,n):deal1(odd,n);/・判断是奇还是偶,并调用对应的函数・/if(n%2==0)printf("Even=%f”,sum);elseprintf("Odd=%f”,sum);getchO;)floateven(intn)(floats=0;inti;for(i=2;i<=n;i+=2)s+=1.0/i;return(s);)floatodd(intn){floats=0;inti;for(i=l;i<=n;i+=2)s+=l.0/i;return(s);)floatdcall(float(*fp)(),intn){floats;)s=(*fp)(n); /・函数的嵌套调用,用指针实现多函数的调用・/return(s);2.3求阶乘倒数之和#include<stdio.h>main()longintrfact(intn);/・递归函数的声明・/longintn,i;floate=0,p;printf("Pleaseinputainteger:");scanf&n);for(i=l;i<=n;i++)(p=rfact(i); /求函数调用・/e=e+l.0/p; /・求和・/}printf("sum=%15.12f\n",e);getchO;)longintrfact(intn) /・递归函数定义・/(if(n<0) /・数据判断・/(printf("Negativeargument!\n");exit(-l); /・正常退出・/}elseif(n-O) /・递归的终点・/return(1);elsereturnn*rfact(n-l); /・递归调用・/第六部分指针及其应用1.1指针与地址voidmain()|inti=3;intj=4;int*p;p=&i；printf(4ti=%d,*p=%d\n,,,i,*p);P=&j；*p=6;printf(4j=%d,*p=%d\nMj,*p);}6.1.2指针变量赋值voidmain()(intnum__i=18;/*定义ー个int型变量num_i*/floatnum__f=5.18;/・定义•个float型变量num_f*/chamum_ch='A';/・定义一个char型变量num_ch*/定义一个指向int型数据的指针变量p_int*/float*p_f;/・定义一个指向float型数据的指针变量p_f*/char*p_ch;/*定义一个指向char型数据的指针变量p_ch*/}printf("*p_int=%d,*p_f=%4.2f,*p_ch=%c\n",*pjnt,*p_f,*p_ch);/*Tl*/printf(nsizep_int=%d,p_f=%d,p_ch=%d\n,',sizeof(p_int),sizeof(p_f),sizeof(p_ch));p_int=&num_i;/・取变量num_int的地址,赋值给p_int*/p_f=&num_f;/・取变量num_f的地址,赋值给p_f*/p_ch=&num_ch;/・取变量num_ch的地址，赋值给p_ch*/printf(nnum_i=%d,*p_int=%d\nH,num_i,*p_int);printf("num_f=%4.2f,*p_f=%4.2f\nM,num_f,*p_f);printf("num_ch=%c,*p_ch=%c\nH,num_ch,*p_ch);6.1.3交换指针变量voidmain()(longnuml,num2;long*p_num1=&numl,*p_num2=&num2,*p;printf("Inputthefirstnumber:M);scanf("％ld”,p_numl);printf("Inputthesecondnumber:M);scanf("％ld”,&num2);printf("numl"％Id,num2=%ld\n,\numl,num2);if(*p_numl>*p_num2レ*如果numl>num2,则交换指针・/p=p_numl;p_numl=p_num2;p_num2=p;)printfC4min=%ld,max=%ld\n,\*p_numl,*p_num2);}6.2.1指向ー维数组的指针#include<stdio.h>voidmain()(longarr[5]={1,234,5};/・定义了一个含有5个长整型元素的数组arr»并初始化・/long*pArr;/・定义了一个指向长整型变量的指针变量pArr*/pArr=arr;/・让pArr指向数组arr,这里没用因对数组名就代表数组首地址。*//・输出pArr,arr,&arr[0]*/printf(npArr:%04x\tarr:%04x\t&arr[0]:%04x\nH,pArr,arr,&arr[0]);/・输出・pArr,pArr[O],arr[0]*/printf(n*pArr:%ld\tpArr[0]:%Id\tarr[OJ:%ld\n",*pArr,pArr[0],arr[OJ);getchar();}6.2.2数组元素的多种表示方法1:用下标表示法voidmain()(inta[8],i;for(i=0;i<8;i++)scanf("％d”,&a[i]);for(i=0;i<8;i++)printf("％d”,a[i]);printf(“\n”)；}方法2:用地址表示法voidmain(){inta[8],i;for(i=0;i<8;i++)scanf("％d”,a+i);for(i=0;i<8;i++)primf("％d”,*(a+i));printf(“\n”)；方法3:用指针表示法voidmain(){inta[8],i,*p；p=&a[0];/*Tl*/for(i=0;i<8;i++)/*T2*/scanf「％d”,p+i);/*T3*/while(p<a+8)/*T4*/printf(<<%d,\*p++);/*T5*/printf(i4\n?,);}6.2.3指针与字符串#includeustdio.h"voidmain()(char*p=MIamastudent!";/*T1*/intlen=0;while(p[len]!=r\O,)(printf("％c”,p[len]);len++;)printf(H\n%sr,,p);/*T2*/printf(,,\nlen=%d\nM,len);}6.2.4字符串复制#include"stdio.h"voidStrCopy(char^pSou,char*pDes)(while("pSou!=ヘ〇')/・与while(*pSou),while(小pSou!=NULL)或while(*pSou!=0)等价*/(*pDes=*pSou;pSou++;pDes++;)*pDes='、〇’;/*Tl*/)voidmain()(inti=0;chars[2OO],d[2OO],*p=s;gets(p);/*T2*/StrCopy(s,d);printf("S=%s\nD=%s\n"，s,d);2.5指针与二维数组#defineM3#defineN4voidmain(){inta[M][N]={l,2,3A5,6J,8,940,ll,12};inti,j;int*p=&a[0][0];/*Tl*/for(i=0;i<M;i++){for(j=0;j<N;j++)printfC%5d,\*(p+i*N+j));printf("\n”)；2.6指针数组#include<stdio.h>voidmain(){inti;charc[3][6]={"boy","woman","girl"};char*pc[3]={c[0],c[l],c[2]};for(i=0;iく3;i++)printf(''pc[%i]=%s=%s\nzz,i,pc[i],c[i]);}2.7指针动态分配#include<stdio.h>#include<stdlib.h>#defineN3voidmain()inti,j;int*p[N];/・定义ー个指针数组,可以存放N个int型指针・/for(i=0;i<N;i++)/・循环,为每个指针动态分配空间。*/{p[i]=(int*)malloc((i+l)*sizeof(inり)；/・分配i+!个元素的空间・/for(j=0;j<i+l;j++)/*然后为当前指针中所指向的每个元素赋值・/P[i][j]=j+l；}for(i=0;i<N;i++)/・输出每个指针中每个元素・/(for(j=0;j<i+l;j++)printf("％5d”,*(p[i]+j));primf("\n”);)for(i=0;i<N;++i)/・非常重要!最后一定要释放为毎个指针所分配的空间・/free(p[i]);getchar();}6.2.8指向指针的指针变量voidmain()(char*pDay[]={"Monday”「Tuesday”JWednesday”JThursday”,"Friday”,”Saturday”,"Sunday"};char**ppDay;inti;for(i=0;i<7;i++)(ppDay=pDay+i;printf("%su*ppDay);)printf("\n’')；}6.3.1指针作为函数的参数#defineN5floatAverScore(float*pa);voidmain(){floatscore[N],av,*sp;inti;sp=score;printf("Pleaseinput%dscores:\nH,N);for(i=0;i<N;i++)scanf(M%f\&score[i]);av=AverScore(sp,N);printf(Haveragescoreis%5.2f*,av);}floatAverScore(float*pa,intn)(inti;floataver,s=0;for(i=0;i<n;i++)s+=*pa++;aver=s/n;returnaver;6.3.2指向函数指针的指针intmax(inta,intb)(returna>b?a:b;)voidmain()(int(*pmax)();/*Tl,定义pmax为函数指针变量・/intx,y,z;pmax=max;/*T2,把被调函数的入口地址赋予该函数指针变量・/printf(MPleaseinputtwonumbersAn'1);scanf("％d%d”,&x,&y);z=(*pmax)(x,y);/*T3,用函数指针变量形式调用函数*/printf(Hmaxmum=%d,\z);}6.3.3指针型函数char*DayName(intn)(staticchar*pDay[]={"Monday”,“Tuesday”,“Wednesday”,"Thursday”,“Friday”,“Saturday”,“Sunday”};returnpDay[n-1];)voidmain()(inti;char*pc;printf("inputDayNo:\nM);scanf("%d",&i);if(i>7lli<l)printf(tfcIIlagalday!\n");pc=DayName(i);printf(HDayNo:%2dis%s\nH,i,pc);)6.3.4main函数的参数voidmain(intargc,charargv[])/*T1*/(inti;printf(t4argc=%d\n",argc);for(i=0;i<argc;i++)printf(H%s",argv[i]);}1将数组元素倒放#include<stdio.h>#include<memory.h>voidswap(int*px,int*py);#defineN100voidresort(intarray[J,intmStartPos,intmAmount)(int*pStart,*pEndj;pStart=&array[mStartPos];/*pStart指向需交换数组元素的起始位置*/pEnd=&array[mStartPos+mAmount-1];/*pEnd指向需交换数组元素的最后,个位置・/for(i=0;i<mAmount/2;i++)(swap(pStart,pEnd);pStart++;pEnd—;})voidswap(int*px,int*py)/・函数定义・/Iinttemp;temp=*px;/・指针的间接引用*/*px=*py;*py=temp;}voidmain()intmret;intnumber[N],mStart,mAmount,i,k=-l;memset(number,O,N);/*将数组中的所有的元素赋值为〇・/printf("pleaseinputdata:\nn);do{k++;mret=scanf("%d",&number[k]);)while(k<N&&mret);fflush(stdin);printf("\nWheredoyouwanttostart:");scanf(n%d",&mStart);printf("\nHowmanynumbersdoyouwanttosort:");scanf("%d",&mAmount);printf("\nYouhadinputarrayasfollow:\n");for(i=0;i<k;i++)printf("%d二numbe巾]);resort(number,mStart,mAmount);printf("\nResortedarrayasfollow:\n");}for(i=0;i<k;i++)printf("%d",number[i]);2求矩阵的最值#include<stdio.h>#defineM100defineN100intMaxVal(intarr[][N],int*m,int*n);voidmain()(intarray[M][N],ij,line,col,max;printf("\nPleaseinputcolumnofarray:");scanf("%d",&col);printf("\nPleaseinputlineofarray:”)；scanf("%d",&line);printf("\nPleaseinputdatausecommabetweendata:");for(i=0;i<line;i++)for(j=0;j<col;j++)scanf("%d",&array[i][j]);printf("\n");for(i=0;i<line;i++)for(j=0;j<col;j++)printf(u%6d",array[i]|j]);printf(H\nn);)printf("\nH);max=MaxVal(array,&line,&col);printf("\nThemaximumvalueis%d:n,max);printf("\nThelineis%d:H,line);printf("\nThecolumnis:%d:",col);}intMaxVal(intarr[][NJ,int*m,int*n)(inti,j,line=0,col=0;intmax=arr[〇][〇];/・先假设arr[〇][〇]是最大的元素・/int(*p)[N];p=arr;for(i=0;i<*m;i++)for(j=0;j<*n;j++)if(max<*(*(p+i)+j)){max=*(*(p+i)+j);line=i;col=j;}m=line;n=col;returnmax;.4.3数据的插入#include<stdio.h>intInsertData(intpArr[],intn,intx);main()(intn=15;inta[100]={68,56,45,45,38,32,21,20,20,20,8,5,2,1,-12);inti,x;printf("\nPleaseinputvalueofx:H);scanf(”％d”,&x);for(i=0;i<n;i++)(if(!(i%10))printf(H\nn);printf(n%5d",a[i]);}n=InsertData(a,n,x);printf(M\nM);n++;for(i=0;i<n;i++)(if(!(i%10))printf(,'\n,');primf("％5d”,a[i]);})intInsertData(intpArr[],intn,intx)(inti,j;/*寻找变量X在数组中的插入位置*/i=0;while(i<n&&x<pArr[i])i++;/・上面的语句运行后,pArr[i]即为变量x在数组中的插入位置,下面的语句是将数组的pArr[i]位置让出来・/for(j=n;j>i;j-)pArr[j]=pArr[j-1];/・将变量x的值存入数组的pArr[i]単元中・/pArr[i]=x;returnn++;第フ部分字符与字符串字符串处理(插入、删除、连接和比较)字符串输入函数get§(