fortran90例子

1、例1、 输入M个实数，将其相加，并输出其和。PROGRAM example_1Implicit noneInteger :n,mReal :t=0,a=0Read *,mDo Read *， a T=t+aN=n+1If (n>=m) exitEnd doPrint*,tEnd program example_1例2、 求I!的阶乘（I=4,8）。Function factor(n) result(fac_result) Implicit none Integer ,intent(in):n Integer,intent(out):fac_result Integer:I Fac_res

2、ult=1 Do I=1,nFac_result=fac_result*I End doEnd function factorProgram example_2 Implicit none Integer :factor,s=0,I Do I=4,8 S=s+factor(i) End doPrint*,sEnd program example_2例3、 输入一个数，判断他是否能被3整除，并输出相应的信息。Program judge Implicit none Integer : n,m Read*,n M=mod(n,3) Select case(m) IF (M= =0) THEN Cas

3、e (0) Print*,yesPrint*,YES Case default ELSE Print*,noPrint*,NO End selectEND IF End program judge 例4、 判断一个整数N是否为素数PROGRAM prime Implicit none Integer :n,I,m Read*,n M= sqrt(real(n) Do I=2,mIf(mod(n,i)= =0) exit End do If (I>m) thenPrint*,yes ElsePrint*,no end ifend program prime例5、 求N的阶乘PROGRAM

4、example_5Implicit noneInteger:n,I=0,fac=1Read*,nDo while (I<7) I=I+1 Fac=fac*IEnd doEnd program example_5例6、 求出全部的水仙花数。（水仙花数是个三位数，其各位数字的立方和等于该数。）program example_6 implicit none integer :I,j,k,m,n ii: do I=1,9 jj: do j=1,9 kk: do k=1,9 m=I*100+j*10+k n=I*3+j*3+k*3 if (m= =n) print*,m end do kk end

5、 do jj end do iiend program exaple_6例7、 牛顿迭代法求方程X*4+4*X+1=0的根program example_7 implicit none integer :I=1,mreal:x0,x,eread*,x0,e,m (m控制迭代次数)do x=(-x0*x0-1)/4 if (abs(x-x0)<=e) exit x0=x I=I+1 If (I>=m) then Print*,not Exit End if End do If (I<m) print*,I,x End program example_7例8、 将例2写成接口块的

6、形式 主程序： Program example_2 Implicit none Interface Function factor(n) result(factor_result) Integer ,intent(in):n Integer:factor_result End function factor End interface Implicit none Integer : s=0,I Do I=4,8 S=s+factor(i) End doPrint*,sEnd program example_2例9、 将例2函数子程序改写成子例行子程序。Subroutine isum(n,isu

7、m_result)implicit noneinteger,intent(in):ninteger,intent(out):isum_resultinteger :Iisum_result=1do I=1,nisum_result=isum_result*Iend doend subroutine peogram example_9 implicit none integer:x,yread*,x call isum(x,y)print*,y=,yend program example_9例10、 子程序作为虚元（虚过程）PROGRAM example_10Implicit noneInter

8、face Function sum(x,y) result(sum_result) Integer,intent(in):x,y Integer,intent(out):sum_result End function sum Function minu(x,y) result(minu_result) Integer,intent(in):x,y Integer,intent(out):minu_result End function minu Integer :a,b Read*,a,bCall proc(a,b,sum)Call proc(a,b,minu)End program exam

9、ple_10Subroutine proc(a,b,fun) Implicit none Function fun(x,y) result (fun_result) Integer,intent(in):x,y Integer,intent(out):fun_result End function fun Integer ,intent(in):a,b Print*,fun(a,b)End subroutineFunction sum(x,y) result(sum_result) Implicit none Integer,intent(in):x,y Integer,intent(out)

10、:sum_result Sum_result=x+y End function sumFunction minu(x,y) result(minu_result) Implicit none Integer,intent(in):x,y Integer,intent(out):minu_result Minu_result=x-y End function minu例11、 模块实现数据共享module exam_module implicit none real:a,b,cend module exam_modulefunction aver3() result (aver_result)

11、use exam_module real:aver_result aver_result=(a+b+c)/3end function aver3function max3() result(max_result) use exam_module real:max_result max_result=a if(b> max_result) max_result=b if (c> max_result) max_result=c end function max3program example_11 use Exam_module real :aver3,max3 read*,a,b,

12、c print*,aver3(),max3()end program example_11注意：（1）USE 模块名，ONLY ：实体名例： use exam_module,only:a,b,此时C不再是共享变量，故C仍需通过虚实结合。 （2）use exam_module ,x->a 将模块中A与程序单元中变量X共享。例12、 递归recursive function fac(n) result(fac_result) implicit none Integer ,intent(in):n Integer,intent(out):fac_result If (n= =0) thenFa

13、c_result=1 Else Fac_result=fac(n-1)*n End ifEnd function facProgram example_12 Implicit none Interface Recursive function fac(n) result(fac_result) Integer ,intent(in):n Integer,intent(out):fac_resultEnd function facEnd interfaceInteger:nRead*,nPrint*,fac(n)End program example_12例13、 编一函数，求两数之和a) 用外部过程实现program example_131 implicit none integer:a,b,sum read*,a,b call add(a,b,sum) print*,sumend program example_131subroutine add(a,b,sum)implicit noneinteger,intent(in):