实验二

#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()%65 + 1;
		printf("20238331%04d\n",number);
	}
	return 0;
}

#include<stdio.h>
int main(){
	char c;
	while(scanf("%c",&c)!=EOF){
	

	switch(c){
		case 'r': printf("stop!\n");break;
		case 'g': printf("go go go\n");break;
		case 'y': printf("wait a minute\n");break;
		default: printf("something must be wrong...\n");break;
		
	}
	c=getchar();
}
	
	return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
int main(){
	printf("猜猜2024年5月哪一天会是你的lucky day\n");
    int number,i,x;
    srand(time(0));
    number=rand()%31 + 1;
    printf("开始喽，你有三次机会，猜吧：");
	for(i=1;i<=3;i++){
		
		scanf("%d",&x);
		
		if(x<number)
		printf("你猜的日期早了，你的lucky day还没到呢\n");
		if(x>number)
		printf("你猜的日期晚了，你的lucky day在前面哦\n");
		if(x==number){
			printf("哇，猜中了:-)\n");
			break;
		}
	    if(i==3){
		printf("次数用完啦。偷偷告诉你，5月你的lucky day是%d号",number);
		break;
		}
    	printf("再猜：");
		}
	return 0;
}

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int n,i,a,m;
    double s;
    while(scanf("%d%d",&n,&a)!=EOF)
 {
    for(i=1,m=0,s=0;i<=n;++i)
       {
           m=m*10+a;
          s+=1.0*i/m;
    }
    printf("n=%d, a=%d, s=%lf",n,a,s);
  }
    system("pause");
    return 0;
}

#include<stdio.h>
int main()
{
	int line,column,x;
	for(line=1;line<=9;line++){
		for(column=1;column<=line;column++){
			x=column*line;
			printf("%dx%d= %d\t",column,line,x);
		}
		printf("\n");
	}
 return 0;
}

#include<stdio.h>
int main()
{
	int i,j,n,k,m;
	printf("input n:");
	scanf("%d",&n);
	for(i=n;i>=1;i--){
		for(k=1;k<=3;k++){
		for(j=1,m=i;j<=(2*n-1);j++,m++){
			if(j>(n+i-1))
			printf("\t");
			else if(m<n)
			printf("\t");
			else if(k==1)
			printf(" O \t");
			else if(k==2)
			printf("<H>\t");
			else if(k==3)
			printf("I I\t");
			}
			printf("\n");
		}
			printf("\n");
	}
 return 0;
}