口袋中有红、黄、蓝、白、黑五种颜色的球若干，每次从口袋中取出3个球。求取法

利用二进制好了

#include <stdio.h>

int main(void)
{
char color[5][8] = {{"red"},{"yellow"},{"blue"},{"white"},{"black"}};
int i, j, k;
int count;
int n = 0;
for (i = 7; i <= 28; i++)
{
count = 0;
if ((i & 1) == 1)
count++;
if ((i & 2) == 2)
count++;
if ((i & 4) == 4)
count++;
if ((i & 8) == 8)
count++;
if ((i & 16) == 16)
count++;

if (count == 3)
{
j = i;
k = 0;
while (j > 0)
{
if ((j & 1) == 1)
printf("%s ", color[k]);
j >>= 1;
k++;
}
printf("\n");
n++;
}

}
printf("\n%d", n);
}

red yellow blue
red yellow white
red blue white
yellow blue white
red yellow black
red blue black
yellow blue black
red white black
yellow white black
blue white black

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