题意：给你n个数，这些数可以互相加或者减，输出在范围【1，sum】里不能通过运算得出的数

思路：套母函数模版

#include <iostream>

#include<cstdio>

using namespace std;

#define N 110

int a[N],c1[10010],c2[10010],v[10010];

int main(int argc, char** argv) {

	int n,sum,i,j,k,ans;

	while(scanf("%d",&n)!=EOF){

		sum=0;

		ans=0;

		for(i=0;i<n;i++){

			scanf("%d",&a[i]);

			sum+=a[i];

		}

		for(i=0;i<=sum;i++){

			c1[i]=0;

			c2[i]=0;

		}

		for(i=0;i<=a[0];i+=a[0])

			c1[i]=1;

		for(i=1;i<n;i++){

			for(j=0;j<=sum;j++){

				for(k=0;k+j<=sum&&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<=sum;j++){

				c1[j]=c2[j];

				c2[j]=0;

			}

		}

		for(i=1;i<=sum;i++)

			if(!c1[i])

				v[ans++]=i;

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

		if(ans){

			for(i=0;i<ans-1;i++)

				printf("%d ",v[i]);

			printf("%d\n",v[i]);

		}

	}

	return 0;

}