#include<stdio.h>

#include<stdlib.h>

#include <time.h>

#define N 30

main()

{

int a,b,c,d,n;

float k,i;

do{

printf("\n请输入1.整数 2.小数 3.退出程序: ");

scanf("%d",&n);

switch(n)

{

case 1:

{

for(i=0;i<N;i++)

{

a=rand()%100+1;

b=rand()%100+1;

c=rand()%4+1;

printf("%d",a);

switch(c)

{

case 1:printf("+");break;

case 2:printf("-");break;

case 3:printf("*");break;

case 4:printf("/");break;

}

printf("%d=\t\t",b);

}

break;

}

break;

case 2:

{

for(i=0;i<N;i++)

{

c=rand()*0.001+1;

d=rand()*0.001+1;

k=rand()%4+1;

printf("%0.2f",k);

switch(c)

{

case 1:printf("+");break;

case 2:printf("-");break;

case 3:printf("*");break;

case 4:printf("/");break;

}

printf("%0.2f=\t",i);

}

break;

}

break;

}

}while(n!=3);

}