C language daily practice - Day 85: The three-color ball problem

C language daily practice
March 8, 2022

Topic description

There are 12 balls in a pocket. It is known that 3 of them are red, 3 are white, and 6 are black. Now take 8 of them, how many possible color combinations are there?

problem analysis

This is a simple combination problem. It goes through all possible combinations and prints the combination of the total sum of 3 color balls to 8.

Code

#include <stdio.h>

int main()
{
    
    
    int red = 0, white = 0, black = 0;
    int cnt = 0;

    for(red = 0; red <= 3; red++)
        for(white = 0; white <=3; white++)
            for(black = 0; black <= 6; black++)
                if(red + white + black == 8)
                {
    
    
                    printf("%-2d --- %d个红球，%d个黑球，%d个黑球\n",
                           ++cnt, red, white, black);

                }
    printf("总共有%d种搭配.\n", cnt);
    return 0;
}

operation result

online reference

Original link: http://c.biancheng.net/cpp/html/3316.html
This code saves a layer of loop.

#include<stdio.h>
int main()
{
    
    
    int m, n, number=0;
    printf("      红球  白球  黑球\n");
    printf("......................\n");
    for( m=0; m<=3; m++ )
        for( n=0; n<=3; n++ )
            if(8-m-n<=6)
                printf(" %2d:    %d    %d    %d\n", ++number, m, n, 8-m-n);
   
    return 0;
}