习题 2-6 排列

（编译环境Dev-C++ 5.11）

#include<stdio.h>
#include<string.h>
int main()
{
    int a[10];
    memset(a, 0, sizeof(a));
    for(int abc = 123; abc <= 329; abc++) {
        int count = 0;
        int def = abc * 2;
        int ghi = abc * 3;
        //分别对其各个位数进行统计
        a[abc%10] = a[abc/10%10] = a[abc/100] = 1;
        a[def%10] = a[def/10%10] = a[def/100] = 1;
        a[ghi%10] = a[ghi/10%10] = a[ghi/100] = 1;
        for(int i = 1; i <= 9; i++)
            count += a[i];
        if(count == 9) 
            printf("%d %d %d\n",abc, def, ghi);
        memset(a, 0, sizeof(a));
    }
    return 0;
}