:+，-，*，/，% 运算，直到输入一个正确的运算符

/****************** *func:+，-，*，/，% 运算， *直到输入一个正确的运算符 ******************/#include<stdio.h>int main(int argc, char *argv[]){    int a, b;     char c;    printf("Please choose! + , - , * , / , or %% \n");    do    {        scanf("%c", &c);    }while(c != '+' && c != '-' && c != '*' && c != '/' && c != '%');    printf("Enter two number!\n");    scanf("%d%d", &a, &b);    switch(c)    {        case '+': printf("a + b = %d\n", a + b); break;        case '-': printf("a - b = %d\n", a - b); break;        case '*': printf("a * b = %d\n", a * b); break;        case '/': printf("a / b = %d\n", a / b); break;        case '%': printf("a %% b = %d\n", a % b); break; //在显示%用%%        default: break;    }    return 0;}