第三题、改错题（20分）
题号【1_2】下列给定程序中，函数fun的功能是：求出两个非零正整数的最大公约数，并作为函数值返回。例如，若给numl和num2分别输入49和2l，则输出的最大公约数为7；若给numl和num2分别输入27和81，则输出的最大公约数为27。
#include <stdio.h>
int fun(int a, int b)
{ int r,t;
if(a<b)
{ t=a;b=a;a=t;}
r=a%b;
while(r!=0)
{ a=b;b=r;r=a%b;}
return(a);
}
main()
{ int num1,num2,a;
printf("input num1 num2: ");
scanf("%d%d",&num1,&num2);
printf("num1=%d num2=%d\n\n",num1,num2);
a=fun(num1,num2);
printf("the maximun common divisor is %d\n\n",a);
}
#include <stdio.h>
int fun(int a, int b)
{ int r,t;
if(a<b)
{ t=a;a=b;b=t;}
r=a%b;
while(r!=0)
{ a=b;b=r;r=a%b;}
return(b);
}
main()
{ int num1,num2,a;
printf("input num1 num2: ");
scanf("%d%d",&num1,&num2);
printf("num1=%d num2=%d\n\n",num1,num2);
a=fun(num1,num2);
printf("the maximun common divisor is %d\n\n",a);
getch();
}
#include <stdio.h>
int fun(int a, int b)
{ int r,t;
if(a<b)
{ t=a;a=b;b=t;}
r=a%b;
while(r!=0)
{ a=b;b=r;r=a%b;}
return(b);
}
main()
{ int num1,num2,a;
printf("input num1 num2: ");
scanf("%d%d",&num1,&num2);
printf("num1=%d num2=%d\n\n",num1,num2);
a=fun(num1,num2);
printf("the maximun common divisor is %d\n\n",a);
}
第一处:{t=a;a=b;b=t}
第二处:return b;
#include <stdio.h>
int fun(int a, int b)
{ int r,t;
if(a<b)
{ t=a;b=a;a=t;}
r=a%b;
while(r!=0)
{ a=b;b=r;r=a%b;}
return(b); //就是最大公约数
}
main()
{ int num1,num2,a;
printf("input num1 num2: ");
scanf("%d%d",&num1,&num2);
printf("num1=%d num2=%d\n\n",num1,num2);
a=fun(num1,num2);
printf("the maximun common divisor is %d\n\n",a);
}