实验二

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
    int num;
    scanf("%d", &num);
    printf("2049%04d\n", num);
    scanf("%d", &num);
    printf("2049%04d\n", num);
    scanf("%d", &num);
    printf("2049%04d\n", num);



    return 0;
}

 

 %04d:右对齐，宽度为4，左边补0

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
    int num;
    while (1)
    {
        scanf("%d", &num);
        printf("2049%04d\n", num);
    }

 

 

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
    char ans1, ans2;
    printf("复习了没? (输入y或Y表示复习了，输入n或N表示没复习) : ");
    ans1 = getchar(); 
    getchar(); 
    printf("\n动手敲代码了没? (输入y或Y表示敲了，输入n或N表示木有敲) : ");
    ans2 = getchar();
    if (ans1,ans2=='y'||ans1,ans2=='Y') 
        printf("\n罗马不是一天建成的:)\n");
    else
        printf("\n罗马不是一天毁灭的。。。\n");


    return 0;
}

 

 

 

吞掉回车不然会赋给ans2

 

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
    char x;
    x = getchar();
    if (x>='0'&&x<='9') 
        printf("%c是数字字符\n", x);
    else if ((x>='a'&&x<='z')||(x>='A'&&x<='Z')) 
        printf("%c是英文字母\n", x);
    else
        printf("%c是其它字符\n", x);
    return 0;
}

 

 

 

 

 

 

#include <stdio.h>
int main()
{
int n, a, j, x;
float sum;
while (scanf_s("%d%d", &n, &a) != EOF) {
j = 1;
sum = 0;
for (x = a; j <= n; j++) {
sum += j / (float)x;
x = x * 10 + a;
}
printf("n=%d,a=%d,sum=%f", n, a, sum);
}
return 0;
}

 

 

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
const int N = 5;
int main()
{
    int x, n;
    srand(time(0));
    for (n = 1; n <= N; n++)
    {
        x = rand() % 100;
        printf("%3d", x);
    }
    printf("\n");
    return 0;
}

 

 

 

 

 

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main()
{
int x, y, n;
srand(time(0));
y = rand() % 31;
n = 1;
printf("猜猜2021年12月哪一天是你的lucky day\n");
printf("开始喽，你有三次机会，猜吧(1~31)：");
while (n <= 3)
{
scanf_s("%d", &x);
if (x < y)
printf("你猜的日期早了，lucky day还没到呢\n再猜(1~31):");
else if (x > y)
printf("你猜的日期晚了，lucky day悄悄溜到前面啦\n再猜(1~31)");
else
printf("bingo\n");
n++;
}
printf("次数用完啦。偷偷告诉你：12月，你的lucky day是%d号", y);
return 0;
}

 

 

#include <stdio.h>
int main()
{
    int i, n;
    i = 1;
    scanf("%d", &n);
    while (i <= n)
    {
        printf(" O \n");
        printf("<H>\n");
        printf("I I\n");
        printf("\n");
        i++;

    }
    return 0;
}

 

 

#include<stdio.h>
int main()
{
    int i, n;
    scanf("%d", &n);
    for (i = 1; i <= n; i++) {
        printf(" O\t");
    }
    printf("\n");
    for (i = 1; i <= n; i++) {
        printf("<H>\t");
    }
    printf("\n");
    for (i = 1; i <= n; i++) {
        printf("I I\t");
    }
    printf("\n");
    return 0;
}

 

 

#include<stdio.h>
int main() {
    int n, i, a, j;
    scanf_s("%d", &n);

    for (j = 0; j < n; j++) {
        for (a = 0; a < j; a++) {
            printf("\t");
        }
        for (i = 0; i < 2 * n - 1 - 2 * j; i++) {
            printf(" o \t");
        }printf("\n");
        for (a = 0; a < j; a++) {
            printf("\t");
        }
        for (i = 0; i < 2 * n - 1 - 2 * j; i++) {
            printf("<H>\t");
        }printf("\n");
        for (a = 0; a < j; a++) {
            printf("\t");
        }
        for (i = 0; i < 2 * n - 1 - 2 * j; i++) {
            printf("I I\t");
        }printf("\n");
    }
    return 0;
}