实验任务2

 

#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起到右四位对齐多余的用0补齐的效果

#include<stdio.h>
int main()
{
    int num;
    while(scanf("%d",&num)!=EOF)
    printf("2049%04d\n", num);
    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();
    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<='9'&&x>='0') 
    printf("%c是数字字符\n", x);
    else if (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,i,denominator,numerator; //分母 分子 
    double sum;
    while(scanf("%d%d",&n,&a) != EOF)
    {
        sum = 0.0;
        denominator = 0;
        numerator=0;
        for(i=1;i<=n;i++)
        {
            denominator = denominator*10 + a;
            numerator=numerator+1;
            sum = sum + (double)numerator/denominator;
        }
        printf("n = %d, a = %d, sum = %f\n",n,a,sum);
        getchar();
    }
    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()
{
    srand(time(0));
    int x,i,n;
    x = rand()%31+1;
    for(i=1;i<=3;i++)
    {
        printf("输入：");
        scanf("%d",&n);
        
        if(n<x) printf("小了\n");
        else if(n>x) printf("大了\n");
        else {
            printf("答对了");
            return 0;
        }
    }
    
    
    printf("%d",x);
    return 0;
}

 

 

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

 

 

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

 

 

#include<stdio.h>
int main()
{
    int n,a,b,c,x,line,d,e;
    scanf("%d",&n);
    x = 2*n+1;
    for(line=1;line<=n;line++){
        e=1;
        for(d=line-1;e<=d;e++){
            printf("\t");
        }
        x = x -2;

        for(a=1;a<=x;a++)
            printf(" O \t");
            printf("\n");
            
        e=1;
        for(d=line-1;e<=d;e++){
            printf("\t");
        }
        for(b=1;b<=x;b++)
            printf("<H>\t");
            printf("\n");
            
        e=1;
        for(d=line-1;e<=d;e++){
            printf("\t");
        }
        for(c=1;c<=x;c++)
            printf("I I\t");
            printf("\n");
        printf("\n");
    
    
    
}
    return 0;
}

 

 for在循环上比while更加简单