实验二

#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;
}

 

#include<stdio.h>
int main()
{
    int num,a; 
    a=1;
    while(a<4){
        scanf("%d", &num);
        printf("2049%04d\n", num); 
        a++;
    }
    return 0;
}

 

#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();
    getchar();
      
    if ((ans1=='y'||ans1=='Y')&&(ans2=='y'||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; 
    }

 

#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 a,b,c,d;
double sum;
while(scanf("%d %d",&b,&a)!=EOF){
c=1;
sum=0;
d=a;
while(c<=b){
    sum = sum + (double)c/a;
        a = a*10+d;
        c++;
}
 printf ("n = %d, a = %d, sum = %f\n",b,c,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,z; 
    srand(time(0)) ;
    x = rand()%31 + 1;
    printf("猜猜12月哪一天是你的luck day\n"); 
    printf("开始喽，你有三次机会，猜吧（1~31）：\n"); 
    for (z=1;z<=3;z++)
    {
    scanf ("%d",&y);
    if (x==y){
    printf("猜对啦，恭喜\n"); 
    break;
    }
    else if(y>x)
    printf("你猜的日期晚了，luck day悄悄溜到前面啦\n");
    else if (y<x)
    printf("你猜的日期早了，luck day还没到呢\n");      
    }
    if (z == 4)
    printf("次数用完啦。偷偷告诉你：12月，你的luck day是%d号\n",x); 
    return 0;
}

 

#include <stdio.h>

int main ()
{
int n,t;
scanf("%d",&n);
t=1;
while (t<=n){
printf(" o \n");
printf("<H>\n");
printf("I I\n");
printf("\n");
t++;
}
return 0;

}