9.11 生成30道四则运算

#include "stdio.h"

#include "math.h"

#include "stdlib.h"

 

void print()

{

for(int i=0;i<=29;i++)

{

int x;
int a=rand()%100;

int b=rand()%100;

 

x=1+(int)(4.0*rand()/(RAND_MAX+1.0));

switch (x)

{

case 1: {printf("%d+%d=\t\t",a,b);break;}

case 2: {printf("%d-%d=\t\t",a,b);break;}

case 3: {printf("%d*%d=\t\t",a,b);break;}

case 4: {printf("%d/%d=\t\t",a,b);break;}

default:{"输出有误！";}

}

}

}

int main(int argc, char* argv[])

{

print();

return 0;

}