题解 | #加减乘除#

//也不是简易计算器，输入很少，整体还是很简单的。
#include "stdio.h"

int recursion(int num){//求阶乘的递归
    if(num == 1)
        return 1;
    else
        return recursion(num-1)*num;
}

int main(){
    int num1,num2;
    char op;
    while (scanf("%d ",&num1)!=EOF){
        scanf("%c",&op);
        switch (op) {
            case '+':
                scanf("%d",&num2);
                printf("%d\n",num1+num2);
                break;
            case '-':
                scanf("%d",&num2);
                printf("%d\n",num1-num2);
                break;
            case '*':
                scanf("%d",&num2);
                printf("%d\n",num1*num2);
                break;
            case '/':
                scanf("%d",&num2);
                if(num2 == 0){
                    printf("error\n");
                    break;
                }
                printf("%d\n",num1/num2);
                break;
            case '%':
                scanf("%d",&num2);
                if(num2 == 0){
                    printf("error\n");
                    break;
                }
                printf("%d\n",num1%num2);
                break;
            case '!':
                printf("%d\n", recursion(num1));
        }
    }
}