四则运算 2.0

#include<stdio.h>
#include<stdlib.h>
#include <time.h>
#define N g
main()
{
    int a,b,k,i,n, c,d,e,f,g;
    do{
    printf("\n请输入题目数量: ");
scanf("%d",&g);
    printf("\n请输入数字类型(1.整数 2.真分数) -1为退出程序: ");
scanf("%d",&n);

    switch(n)
    {
    case 1:
    {

    for(i=0;i<N;i++)
    {
    a=rand()%100+1;
    b=rand()%100+1;
    k=rand()%4+1;
    printf("%d",a);
    switch(k)
    {
    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++)
    {
    e=rand()%100+1;
    f=rand()%100+1;
    k=rand()%4+1;
    if ( e>=f)
        printf("%d/%d",f,e);
    else
        printf("%d/%d",e,f);
    switch(k)
    {
    case 1:printf("+");break;
    case 2:printf("-");break;
    case 3:printf("*");break;
    case 4:printf("/");break;
    }
    c=rand()%100+1;
    d=rand()%100+1;
    if ( c>=d)
        printf("%d/%d=\t\t",d,c);
    else
        printf("%d/%d=\t\t",c,d);
    }
    break;
    }
    break;
    }
    }while(n!=-1);
}