CF687C. The Values You Can Make[背包DP]

C. The Values You Can Make

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Pari wants to buy an expensive chocolate from Arya. She has n coins, the value of the i-th coin is ci. The price of the chocolate is k, so Pari will take a subset of her coins with sum equal to k and give it to Arya.

Looking at her coins, a question came to her mind: after giving the coins to Arya, what values does Arya can make with them? She is jealous and she doesn't want Arya to make a lot of values. So she wants to know all the values x, such that Arya will be able to make xusing some subset of coins with the sum k.

Formally, Pari wants to know the values x such that there exists a subset of coins with the sum k such that some subset of this subset has the sum x, i.e. there is exists some way to pay for the chocolate, such that Arya will be able to make the sum x using these coins.

Input

The first line contains two integers n and k (1  ≤  n, k  ≤  500) — the number of coins and the price of the chocolate, respectively.

Next line will contain n integers c1, c2, ..., cn (1 ≤ ci ≤ 500) — the values of Pari's coins.

It's guaranteed that one can make value k using these coins.

Output

First line of the output must contain a single integer q— the number of suitable values x. Then print q integers in ascending order — the values that Arya can make for some subset of coins of Pari that pays for the chocolate.

Examples

input

6 18
5 6 1 10 12 2

output

16
0 1 2 3 5 6 7 8 10 11 12 13 15 16 17 18 

input

3 50
25 25 50

output

3
0 25 50 

---

很水........

Let dpi, j, k be true if and only if there exists a subset of the first i coins with sum j, that has a subset with sum k. There are 3 cases to handle:

• The i-th coin is not used in the subsets.
• The i-th coin is used in the subset to make j, but it's not used in the subset of this subset.
• The i-th coin is used in both subsets.

So dpi, j, k is equal to dpi - 1, j, k OR dpi - 1, j - ci, k OR dpi - 1, j - ci, k - ci.

f[i][j][k]表示前i个coin能否凑成j价值再从凑成j价值的里面凑出k价值
f[0][0][0]=1
第一维可以滚掉

//
//  main.cpp
//  cf687c
//
//  Created by Candy on 9/20/16.
//  Copyright © 2016 Candy. All rights reserved.
//

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N=505;
int read(){
    char c=getchar();int x=0,f=1;
    while(c<'0'||c>'9'){if(c=='-')f=-1; c=getchar();}
    while(c>='0'&&c<='9'){x=x*10+c-'0'; c=getchar();}
    return x*f;
}
int n,v,c[N],cnt=0;
int f[N][N];
void dp(){
    f[0][0]=1;
    for(int i=1;i<=n;i++){
        for(int j=v;j>=0;j--)
            for(int k=v;k>=0;k--)
                if(j-c[i]>=0){
                    f[j][k]|=f[j-c[i]][k];
                    if(k-c[i]>=0) f[j][k]|=f[j-c[i]][k-c[i]];
                }
    }
}
int main(int argc, const char * argv[]) {
    n=read();v=read();
    for(int i=1;i<=n;i++) c[i]=read();
    dp();
    for(int i=0;i<=v;i++) if(f[v][i]) cnt++;
    printf("%d
",cnt);
    for(int i=0;i<=v;i++) if(f[v][i]) printf("%d ",i);
    return 0;
}