小项目（一）：整数四则运算练习

//开发者：邵义豪
//开发时间：2021.1.23
//版本：1.0
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main()
{
    
    
    int a, b, result, count = 0;
    time_t start, end;
    printf("您好！我是开发者小邵 syh。\n");
    printf("欢迎使用本产品！祝您使用愉快！\n\n");
    printf("您想要进行什么运算？（请输入算术符号）\n");
    char sign, ch;
    scanf("%c", &sign);
    srand((int)time(NULL));
    switch (sign)
    {
    
    
        case '+':
    label1: a = (int)rand() % 100;
            b = (int)rand() % 100;
            printf("%d + %d = ", a, b);
            start = time(NULL);
            scanf("%d", &result);
            end = time(NULL);
            getchar();//消化回车
            if (result == a + b)
            {
    
    
                count ++;
                printf("%d + %d = %d\n", a, b, result);
                printf("祝贺你!回答正确！\n");
                printf("用时：%.1f s\n", difftime(end, start));
            }
            else
            {
    
    
                printf("%d + %d = %d\n", a, b, a+b);
                printf("对不起，回答错误！\n");
            }
            printf("\n继续吗?(Y or N)");
            putchar(10);
            ch = getchar();
            putchar(10);
            if (ch == 'Y')
                goto label1;
            else
                break;
        case '-':
        label2: a = (int)rand() % 100;
                b = (int)rand() % 100;
                printf("%d - %d = ", a, b);
                start = time(NULL);
                scanf("%d", &result);
                end = time(NULL);
                getchar();
                if (result == a - b)
                {
    
    
                    count ++;
                    printf("%d - %d = %d\n", a, b, result);
                    printf("祝贺你!回答正确！\n");
                    printf("用时：%.1f s\n", difftime(end, start));
                }
                else
                {
    
    
                    printf("%d - %d = %d\n", a, b, a-b);
                    printf("对不起，回答错误！\n");
                }
                printf("continue?(Y or N)");
                putchar(10);
                ch = getchar();
                if (ch == 'Y')
                    goto label2;
                else
                    break;
        case '*':
        label3: a = (int)rand() % 100;
                b = (int)rand() % 100;
                printf("%d * %d = ", a, b);
                start = time(NULL);
                scanf("%d", &result);
                end = time(NULL);
                getchar();
                if (result == a * b)
                {
    
    
                    count ++;
                    printf("%d * %d = %d\n", a, b, result);
                    printf("祝贺你!回答正确！\n");
                    printf("用时：%.1f s\n", difftime(end, start));
                }
                else
                {
    
    
                    printf("%d * %d = %d\n", a, b, a*b);
                    printf("对不起，回答错误!\n");
                }
                printf("continue?(Y or N)");
                putchar(10);
                ch = getchar();
                if (ch == 'Y')
                    goto label3;
                else
                    break;
        default:
        case '/':
        label4: do{
    
    
                    a = (int)rand() % 100;
                    b = (int)rand() % 100;
                }while(a % b != 0);
                printf("%d / %d = ", a, b);
                start = time(NULL);
                scanf("%d", &result);
                end = time(NULL);
                getchar();
                if (result == a / b)
                {
    
    
                    count ++;
                    printf("%d / %d = %d\n", a, b, result);
                    printf("祝贺你!回答正确！\n");
                    printf("用时：%.1f s\n", difftime(end, start));
                }
                else
                {
    
    
                    printf("%d / %d = %d\n", a, b, a/b);
                    printf("对不起，回答错误!\n");
                }
                printf("continue?(Y or N)");
                putchar(10);
                ch = getchar();
                if (ch == 'Y')
                    goto label4;
                else
                    break;
    }
    printf("您一共答对了%d道题。\n\n", count);
    printf("感谢您使用本产品！\n祝学习进步！\n");
    return 0;
}