称重量问题

今天在优快云上逛，看有一人提如下……

 

问题：
只有1克，2克，5克，7克，13克五个砝码，给定任意一个质量的物体，求解能否被称量（而且数字只能用一次，只能用加法）

 

解决：
用递归可以解决！

#include "stdafx.h"
#include <stdio.h>

int poise[] = {1, 2, 5, 7, 13};
int  flag[] = {0, 0, 0, 0, 0};

int AddPoise(int count, int current, int total)
{
    for(int i = 0; i < 5; ++i)
    {
        if (flag[i])
            continue;

        flag[i] = 1;
        --count;

        if (current + poise[i] == total)
            return total;
        else if (count) 
        {
            if ( AddPoise(count, current + poise[i], total) == total)
                return total;
        }

        flag[i] = 0;
        ++count;            
    }

    return current;
}


int main()
{
    int weight;
    printf("Please input the weight(1-28):");
    scanf("%d", &weight);
    printf("/n");

    int w = AddPoise(5, 0, weight);

    if ( w == weight)
    {
        printf("The answer:");
        for(int i = 0; i < 5; ++i)
            if (flag[i])
                printf("%d,", poise[i]);

        printf("/n");
    }
    else
    {
        printf("NO ANSWER!/n");
    }
    
    printf("/n/nPress a key to exit...");    
    char ch;
    scanf("%d", &ch);
    
    return 0;
}