HDU1709 The Balance（母函数）

The Balance

题目链接：

http://acm.hdu.edu.cn/showproblem.php?pid=1709

解题思路：

有了上次对母函数的理解，这道题应该不难吧。

AC代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

int main(){
    int n;
    while(scanf("%d",&n) != EOF){
        int i,j,k,num = 0;
        int a[110],c1[10010],c2[10010],cnt[10010];
        for(i = 0; i < n; i++){
            scanf("%d",&a[i]);
            num += a[i];
        }
        memset(c1,0,sizeof(c1));
        memset(c2,0,sizeof(c2));
        c1[0] = 1;
        c1[a[0]] = 1;
        for(i = 1; i < n; i++){
            for(j = 0; j <= num; j++){
                for(k = 0; k+j<=num && k<=a[i]; k+=a[i]){
                    if(k>=j)
                        c2[k-j] += c1[j];
                    else
                        c2[j-k] += c1[j];
                    c2[j+k] += c1[j];
                }
            }
            for(j = 0; j <= num; j++){
                c1[j] = c2[j];
                c2[j] = 0;
            }
        }
        for(i = 1,j = 0;i <= num; i++)
            if(c1[i] == 0)
                cnt[j++] = i;
        if(j == 0)
            printf("0\n");
        else{
            printf("%d\n",j);
            for(i = 0; i < j-1; i++)
                printf("%d ",cnt[i]);
            printf("%d\n",cnt[j-1]);
        }
    }
    return 0;
}