程序未运行，直接显示“按任意键继续”

Question

问题遇到的现象和发生背景

初学者自己编辑的一个程序，软件没有报错，但是运行没有结果，直接显示“按任意键继续. . .”

用代码块功能插入代码，请勿粘贴截

#include <stdio.h>
void man()
{
    float c,d,e;
    char a,b,f='v';
    printf("wellcome!\n  --> Do you want to enter this program?(please input yes or no.)");
    scanf("%c",&a);
    if(a=='yes')
    {
        while(f!='end')
        {
            printf("Please input sign of arithmetic.(+,-,*,/)\n\a");
            scanf("%C",&b);
            printf("please input number of a and b.\n");
            scanf("%f %f",&c,&d);
            if(b='+')
                {
                e=c+d;
                printf("the answer is %f",e);
                }
            if(b='-')
                {
                e=c-d;
                printf("the answer is %f",e);
                }
            if(b='*')
                {
                e=c*d;
                printf("the answer is %f",e);
                }    
            if(b='/')
                {
                    if(d!=0)        
                    {
                    e=c/d;
                    printf("the answer is %f",e);
                    }
                    else
                    printf("error!");
                    
            printf("if you want to end ,please input 'end'.\n");
            scanf("%c",&f);
                }
            
            }
            
            
        }
    printf("ending\n ");
    
}

运行结果及报错内容

未运行，直接显示“按任意键继续”

Answer 1

主函数格式：
int main() {
// 逻辑代码
return 0;
}