c语言初学必背代码.docx

/1.成绩判断#include int main()/成绩int score;printf(请输入你的成绩:n);scanf(%d, &score);/判断if(score =0 & score 60)printf(不及格n);else if(60 = score & score 80)printf(中等n);else if(80 = score & score 100)printf(优秀n);elseprintf(输入错误!n);/2.计算1到100的和#include int main()int sum = 0;/存结果变量int i;for(i=1;i = 100;i+)sum = sum + i;printf(sum=%dn, sum);/3.最大公约数#include /求m,n的最大公约数int main()int m, n;int i, k;printf(请输入两个数:);scanf(%d %d, &m, &n);/三元运算符找较小的那个k = m =1; i-)/这是公约数if(m % i = 0) & (n % i =0)printf(最大公约数是%dn, i);break;/跳出for循环/4.最小公倍数#include /求m,n的最小公倍数int main()int m, n;int max, min;/m,n中较大,较小的那个int k;/max, 2*max, 3*max, .printf(请输入两个数:);scanf(%d %d, &m, &n);/也可以交换m,n,保证m小n大max = m n ? m : n;min = m n ? m : n;k = max;/从max开始while(k % min != 0)k += max;/每次倍增printf(最小公倍数是%dn, k);/5.金字塔#include /金字塔int main()int i;/外层int j;/内层for(i=1;i=10;i+)/当前是在第i行/先补空格10-i个for(j=1;j=10-i;j+)printf( );/再打2i-1个*for(j=1;j=2*i-1;j+)printf(*);printf(n);/6.九九乘法表#include /打印九九乘法表int main()int i,j;for(i=1;i=9;i+)/外层一定是9行for(j=1; j=i; j+)/内层第几行走几遍printf(%d*%d=%d , i, j, i*j);printf(n);/7.百钱买百鸡#include /*百钱买百鸡,类似1,2,5凑100银币问题*/int main2()int i,j;/公鸡，母鸡个数for(i=0; i=20; i+)/公鸡for(j=0; j=33; j+)/母鸡if( (15*i + 9*j + (100-i-j) = 300)printf(公鸡%d，母鸡%d，小鸡%dn, i, j, 100-i-j);/1,2,5凑100银币问题int main3()int count = 0;/情况数int i,j;/5分个数，2分个数for(i=0; i=20; i+)/5分个数for(j=0; j=50; j+)/2分个数if( ( 5*i + 2*j ) = 100 ) count+;printf(%d: 5分%d个，2分%d个，1分%d个n, count, i, j, 100-5*i-2*j);/8.一维数组的最大值、最小值、平均值#include #define N 10/宏定义常量int main()int i;/下标索引int max, min;double sum = 0;/累加和int aN = 58, 58, 96, 100, 25, 55, 66, 88, 99, 77;max = a0;/假设第一个最大min = a0;/假设第一个最小for(i=1; i max)/比最大值还大max = ai;/你才是最大if(ai min)/比最小值还小min = ai;/你才是最小sum += ai;printf(max=%d, min=%dn, max, min);printf(average = %.2lfn, sum/N);/9.二维数组的最大值、最小值、平均值#include int main()int i; /第几行int j; /第几列int a34 = 1,2,3,4, 5,-6,7,8, 9,19,39,0;int max = a00;/假设你最大int min = a00;/假设你最小double average;/平均值double sum = 0; /总和for(i=0; i3; i+)/必定3行for(j=0; j max)max = aij;if(aij min)min = aij;printf(n);average = sum / (3*4);printf(max=%d, min=%d, avg=%.2lfn, max, min, average);/10.二维数组转置#include /二维数组转置：行变列，列变行int main()int i; /第几行int j; /第几列int a34 = 1,2,3,4, 5,-6,7,8, 9,19,39,0;int b43;for(i=0; i3; i+)for(j=0; j4; j+)printf(%5d, aij);printf(n);/矩阵转置for(i=0; i3; i+)for(j=0; j4; j+)bji = aij;for(i=0; i4; i+)for(j=0; j3; j+)printf(%5d, bij);printf(n);/11.冒泡排序#include #define N 10/宏定义常量int main()int i;/下标索引int j;int tmp;/临时交换用int aN = 58, 58, 96, 100, 25, 55, 66, 88, 99, 77;/外层循环一定是N-1for(i=0; iN-1; i+)/两两交换，大的往后走for(j=0; j aj+1)tmp = aj;aj = aj+1;aj+1 = tmp;for(i=0; iN; i+)printf(%d , ai);printf(n);/12.结构冒泡排序#include /结构定义,用户自定义类型typedef struct studentchar sno20;/学号char name20;/姓名int age;/年龄char gender;/性别char tel20;/电话;int main()int i;int j;double sum = 0;struct student tmp;/两两交换临时用;/结构数组struct student team5;for(i=0; i5; i+)printf(请输入第%d个队员的信息:n, i+1);scanf(%s %s %d %c %s, teami.sno, , &teami.age, &teami.gender, teami.tel);/按年龄冒泡排序for(i=0; i5; i+)for(j=0; j teamj+1.age)tmp = teamj;teamj = teamj+1;teamj+1 = tmp;/取值printf(%-12s %-10s %-5s %-5s %-15sn, 学号, 姓名, 年龄, 性别, 电话);for(i=0; i5; i+)printf(%-12s %-10s %-5d %-5c %-15sn, teami.sno, , teami.age, teami.gender, teami.tel);/13.结构数组找年龄最大值#include /结构定义,用户自定义类型typedef struct studentchar sno20;/学号char name20;/姓名int age;/年龄char gender;/性别char tel20;/电话;int main()int i;struct student tmp;/找最大临时用/结构数组struct student team5;for(i=0; i5; i+)printf(请输入第%d个队员的信息:n, i+1);scanf(%s %s %d %c %s, teami.sno, , &teami.age, &teami.gender, teami.tel);/取值printf(%-12s %-10s %-5s %-5s %-15sn, 学号, 姓名, 年龄, 性别, 电话);for(i=0; i5; i+)printf(%-12s %-10s %-5d %-5c %-15sn, teami.sno, , teami.age, teami.gender, teami.tel);/找学号最大的那一个tmp = team0;for(i=1; i 0 )tmp = teami;printf(学号最大的队员如下:n);printf(%-12s %-10s %-5d %-5c %-15sn, tmp.sno, , tmp.age, tmp.gender, tmp.tel);/14.文件读写#include #include /结构定义,用户自定义类型typedef struct studentchar sno20;/学号char name20;/姓名int age;/年龄char gender;/性别char tel20;/电话;/文件读写int main()struct student * s, * p1;/个数未知FILE * fp;int i, n = 0;char buf1024;/fgets缓冲区/打开文件fp = fopen(e:test.txt, r);while(fgets(buf, 1024, fp) != NULL)n+;fclose(fp);/指向一个可以存储n个student结构的内存空间s = (struct student *)malloc(sizeof(struct student) * n);p1 = s;/不要动头位置s的值/打开文件fp = fopen(e:test.txt, r);for(i=0; isno, p1-name, &p1-age, &p1-gender, p1-tel);p1+;fclose(fp);p1 = s;for(i=0; isno, p1-name, p1-age, p1-gender, p1-tel);free(s);/15.输入三角形三边长计算周长和面积#include #include int main() double area,perimeter,s,a,b,c; printf(请输入三边长 a b c:); scanf(%lf%lf%lf,&a,&b,&c); if(a+bc) & (a+cb) & (b+ca) s=(a+b+c)/2; area=sqrt(s*(s-a)*(s-b)*(s-c); perimeter=a+b+c; printf(area=%.2f,perimeter=%.2fn,area,perimeter); else printf(三边长无法构成三角形。n); return 0; /16.输入年份和月份输出对应那一月的天数，要处理闰年#includeint main()int year,month;int leap =0;scanf(%d %d,&year,&month);if(year %4=0 & year %100 !=0) | year %400 =0) /闰年2月29天leap=1;switch(month)case 1:case 3:case 5:case 7:case 8:case 10:case 12:printf(31);break;case 4:case 6:case 9:case 11:printf(30);break;case 2:printf(%d,28+leap);break;default:printf(error);break;return 0;/17.1，2，5分硬币问题#include int main()int sum = 0;for(int i=0; i=20; i+)/5分for(int j=0; j=50; j+)/2分if(5*i + 2*j = 100)sum+;elsebreak;printf(%dn, sum); /18.100到200所有的素数#include int main()int i,j,n;/外层for(i=100; i=200; i+)n = i;/内层for(j=2;j=n-1;j+)if(n%j = 0)break;/不是素数if(j=n)/没找到printf(%d是素数n, n);elseprintf(%d不是素数n, n);/19.输入一个数n，计算12+22+32+n2#include int main()int sum = 0;int i,