随机生成n道100以内加减乘除运算，打印无法对其

Question

求指点如何让打印结果对齐得漂亮些，还有该程序是否还有可以优化的地方，求解。

#include <stdio.h>
#include<time.h>
#include<stdlib.h>

double add(double x,double y){
    return x+y;
}

double sub(double x,double y){
    return x-y;
}

double mul(double x,double y){
    return x*y;
}

double div(double x,double y){
    return x/y;
}

double calc(double x,double y,int z){
  switch(z){
      case 1: return add(x,y);     break;
      case 2: return sub(x,y);     break;
      case 3: return mul(x,y);     break;
      case 4: return div(x,y);     break;
  }
    
}

void print(double x,double y,int z){
    switch(z){
    case 1: printf("%-2.2f+%-2.2f=%6.2f   ",x,y,calc(x,y,1));     break;
      case 2: printf("%-2.2f-%-2.2f=%6.2f   ",x,y,calc(x,y,2));     break;
      case 3: printf("%-2.2f*%-2.2f=%6.2f   ",x,y,calc(x,y,3));     break;
      case 4: printf("%-2.2f/%-2.2f=%6.2f   ",x,y,calc(x,y,4));     break;    
    }
}


int main() {
    double a=0.0;
    double b=0.0;
    int c=0;
    int i=1000;
    int count=0;

srand((unsigned)time(NULL));

    
    while(i--) {
    a=rand()%100+1;
    b=rand()%100+1;
    c=rand()%4+1;
    if(a<b||(int)a%(int)b!=0){//该处把出现负数的情况和除不尽的情况去掉，适合给小学低年级的孩子出题 
        i++;
        continue;
    }

     print(a,b,c);
     count++;
     if(count%6==0)
     printf("\n");
    }



    return 0;
}

Answer 1

#include <stdio.h>
#include <time.h>
#include <stdlib.h>

int main()
{
    int a, b, c;
    srand(time(NULL));
    for (int i = 1; i <= 1000; i++)
    {
        do
        {
            a = rand() % 100 + 1;
            b = rand() % 100 + 1;
            c = rand() % 4 + 1;
        } while (a < b || a % b != 0);

        switch (c)
        {
        case 1:
            printf("%2d + %2d = %d\t", a, b, a + b);
            break;
        case 2:
            printf("%2d - %2d = %d\t", a, b, a - b);
            break;
        case 3:
            printf("%2d * %2d = %d\t", a, b, a * b);
            break;
        case 4:
            printf("%2d / %2d = %d\t", a, b, a / b);
            break;
        default:
            break;
        }
        if (i % 5 == 0)
            printf("\n");
    }

    return 0;
}