作业2

task 1

#include<stdio.h>
#include<stdlib.h>
#include <time.h>

#define N 5

int main() {

    int number;
    int i;

    srand(time(0));

    for (i = 0;i < N;++i) {
        number = rand() % 500 + 1;
        printf("20228329%04d\n", number);
    }
    return 0;
}

 

 task 2

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

int main()
{
    int luckyday, a, i;
    srand(time(0));
    luckyday = rand() % 30 + 1;
    printf("猜猜2022年11月哪一天会是你的lucky day\n");
    printf("开始喽，你有三次机会，猜吧（1-30）：");
    for (i = 1; i <= 3; ++i) {
        scanf_s("%d", &a);
        if (a == luckyday) {
            printf("哇，猜中了\n");
            exit(0);
        }
        else if (a < luckyday){
            printf("你猜的日期早了，你的luckyday还没到呢\n");
            if (i == 3)
            {
                break;
            }
            printf("再猜：");
        }
        else{
            printf("你猜的日期晚了，你的luckyday已经过了\n");
            if (i == 3){
                break;
            }
            printf("再猜：");
        }
    }
    printf("次数用完了，偷偷告诉你：11月，你的luckyday是%d号\n", luckyday);

    return 0;
}

 

 task 3

#include <stdio.h>
int main()
{
    char colour;


    while (1) {
        colour = getchar();
        switch (colour) {
        case 'r': printf("Stop!"); break;
        case 'g': printf("go go go"); break;
        case 'y': printf("wait a minute"); break;
        default: printf("something must be wrong..."); break;
        }
        getchar();
        getchar();
    }
    return 0;
}

 

 task 4

#include <stdio.h>
#include <stdlib.h>
#include<math.h>
int main()
{
    int n, a, i;
    double s;
    while (1) {
        scanf_s("%d%d", &n, &a);
        for (i = 1, s = 0; i <= n; ++i);
        {
            s += 1.0 * i / pow(a, i);
        }
        printf("n=%d,a=%d,s=%lf", n, a, s);
        printf("\n");
    }

    return 0;
}

 

 task 5

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

int main(){
    int l, r;
    for (l = 1; l <= 9; l++){
        for (r = 1; r <= l; r++){
            int ans;
            ans = l * r;
            printf("%d*%d = %.2d  ", r, l, ans);
        }
        printf("\n");
    }
    return 0;
}

 

 

 task 6

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int n, i, x, y;
    printf("input:");
    scanf_s("%d", &n);
    for (i = 0; i < n; i++)
    {
        for (y = 0; y < i; y++)printf("        ");
        for (x = 0; x < (n - i) * 2 - 1; x++)printf(" O \t");
        printf("\n");
        for (y = 0; y < i; y++)printf("        ");
        for (x = 0; x < (n - i) * 2 - 1; x++)printf("<H>\t");
        printf("\n");
        for (y = 0; y < i; y++)printf("        ");
        for (x = 0; x < (n - i) * 2 - 1; x++)printf("I I\t");
        printf("\n");
    }
    system("pause");
    return 0;
}