Go: ///
// File:  0529.go
// Author: ymiyamoto
//
// Created on Wed Feb 28 20:39:28 2018
//
package main

import (
	"fmt"
	"sort"
)

func max(n, m int) int {
	if n < m {
		return m
	} else {
		return n
	}
}

func main() {
	for {
		var N, M int
		fmt.Scan(&N, &M)
		if N == 0 && M == 0 {
			break
		}

		arr := make([]int, N+1)
		for i := 1; i <= N; i++ {
			fmt.Scan(&arr[i])
		}
		sort.Ints(arr)

		sums := make([]int, len(arr)*len(arr))
		for i := 0; i < len(arr); i++ {
			for j := 0; j < len(arr); j++ {
				sums[i+j] = arr[i] + arr[j]
			}
		}
		sort.Ints(sums)

		m := 0
		for i := 0; i < len(sums); i++ {
			rem := M - sums[i]
			if rem >= 0 {
				index := sort.Search(len(sums), func(i int) bool { return sums[i] > rem }) - 1
				if index >= 0 {
					m = max(m, sums[i]+sums[index])
				}
			}
		}
		fmt.Println(m)
	}
}

C++: #include <iostream>
#include <sstream>
#include <vector>
#include <list>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
using namespace std;

typedef long long INT;
typedef vector <INT> VI;
typedef set <INT> SI;

INT solve( const VI& Q, INT M ) {
    INT answer = 0;
    int n = Q.size();
    for ( int i = 0; i < n; ++ i ) {
        int q = Q[i];
        int L = 0;
        int R = n;
        INT m = M - q;
        while ( L < R ) {
            int p = ( R - L ) / 2 + L;
            INT t = q + Q[p];
            if ( t > M ) t = 0;
            answer = max( answer, t );
            if ( Q[p] > m ) {
                R = p;
            } else {
                L = p + 1;
            }
        }
    }
    return answer;
}

int main() {
    int n, m;
    while ( cin >> n >> m ) {
        if ( n == 0 && m == 0 ) break;
        VI P( n + 1 );
        for ( int i = 0; i < n; ++ i ) {
            INT p;
            cin >> p;
            P[i] = p;
        }
        P[n] = 0;
        VI Q( ( n + 1 ) * ( n + 1 ) );
        for ( int i = 0; i < n + 1; ++ i ) {
            for ( int j = 0; j < n + 1; ++ j ) {
                Q[i * ( n + 1 ) + j] = P[i] + P[j];
            }
        }
        sort( Q.begin(), Q.end() );
        cout << solve( Q, m ) << endl;
    }
    return 0;
}

C++: #include <cstdio>
#include <cctype>
#include <utility>
#include <vector>
#include <algorithm>
#include <array>
#include <numeric>
using namespace std;

const auto gcu = getchar_unlocked;
const auto pcu = putchar_unlocked;
#define _T template <typename T>
#define _HT template <typename H, typename... T>
#define _il inline
#define _sc _il bool scan
_T T in(int c){T n=0;int m=1;while(isspace(c)){c=gcu();}if(c=='-')m=-1,c=gcu();
	do{n=10*n+(c-'0'),c=gcu();}while(c>='0'&&c<='9');return m*n;}
_il int in() {return in<int>(gcu());}
_T T scan(T &n){int c=gcu();return c==EOF?false:(n=in<T>(c),true);}
_sc(char &c){c=gcu();gcu();return c!=EOF;}
#ifdef _GLIBCXX_STRING
_sc(string &s){int c;s="";
	for(;;){c=gcu();if(c=='\n'||c==' ')return true;else if(c==EOF)return false;s+=c;}}
#endif
_HT _sc(H &h, T&&... t){return scan(h)&&scan(t...);}
#define _ot _il void out
#define _ol _il void outl
_ot(bool b) {pcu('0'+b);}
_ot(const char *s){while(*s)pcu(*s++);}
_ot(char c){pcu(c);}
#ifdef _GLIBCXX_STRING
_ot(string s){for(char c:s)pcu(c);}
#endif
_T _ot(T n){static char b[20];char *p=b,m=n<0?pcu('-'),-1:1;
	if(!n)*p++='0';else while(n)*p++=n%10*m+'0',n/=10;while(p!=b)pcu(*--p);}
_ol(){out('\n');}
#ifdef _GLIBCXX_VECTOR
_T _ot(vector<T> &v){for(T &x:v)out(&x == &v[0]?"":" "),out(x);outl();}
#endif
_HT _ot(H&& h, T&&... t){out(h);out(move(t)...);}
template <typename... T> _ol(T&&... t){out(move(t)...);outl();}

void radix_sort(vector<int>::iterator b,vector<int>::iterator e) {
    vector<int> t(e - b);
    array<int, 256> c, s;
    for (int i = 0; i < 32; i += 8) {
        fill(c.begin(), c.end(), 0);
        for_each(b, e, [&](int j) {c[(j >> i) & 255]++;});
        s[0] = 0;
        partial_sum(c.begin(), c.end() - 1, s.begin() + 1);
        for_each(b, e, [&](int j) {t[s[(j >> i) & 255]++] = j;});
        copy(t.begin(), t.end(), b);
    }
}

int main() {
	for (int N, M; N = in(), M = in();) {
		vector<int> t(N), u;
		for (int &p: t)
			p = in();
		t.push_back(0);
		radix_sort(t.begin(), t.end());
		for (auto i = t.begin(); i != t.end(); i++)
			for (auto j = i; j != t.end(); j++)
				if (*i + *j <= M)
					u.push_back(*i + *j);
		radix_sort(u.begin(), u.end());
		int r = 0;
		for (auto i = u.begin(), e = u.end() - 1; i <= e; i++) {
			for (; *i + *e >= M; e--)
				;
			r = max(r, *i + *e);
		}
		outl(r);
	}
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>

#define MAX_N 1000

using namespace std;

int p[MAX_N + 1];
vector<int > lat;

int N;
int M;

int solve(){
	int res = 0;
	int fake;

	sort(p,p + N + 1);
	for(int i = 0;i <= N;i++){
		for(int j = i;j <= N;j++){
			lat.push_back(p[i] + p[j]);
		}
	}

	sort(lat.begin(),lat.end());
	vector<int >::iterator ite;

	for(int i = 0;i <= N;i++){
		for(int j = 0;j <= N;j++){
			fake = M - (p[i] + p[j]);
			if(fake < 0) break;
			ite = upper_bound(lat.begin(),lat.end(),fake);
			res = max(res,p[i] + p[j] + *(ite - 1));
		}
	}

	return res;
}
			
			

int main(){

	while(true){
	scanf("%d%d",&N,&M);
	if(N == 0 && M == 0) break;
	lat.clear();
	for(int i = 1;i <= N;i++){
		scanf("%d",p + i);
	}

	int ans = solve();

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

	}
}

C++: 
#include<stdio.h>
#include<stdlib.h>
#include<math.h>

int main()
{
	int ans[4];
	int temp;
	double energy,energy_min,energy_now;
	int M, N;
	int* p;
	int i, j;
	double T=100;
	int ret;
	while (1) {
		scanf("%d%d", &N, &M);
		p = (int*)malloc((N+1) * sizeof(int));
		for (i = 0; i < N; i++) {
			scanf("%d", &p[i]);
		}
		p[N] = 0;
		if (N == M && N == 0) {
			break;
		}
		energy_min = pow(10, 300);
		for (j = 0; j < 4; j++) {
			ans[j] = p[(int)((double)(rand() + 1) / (RAND_MAX + 2)*(N+1))];
		}
		
		for (T = 1000000; T > 100; T--) {
			for (j = 0; j < 4; j++) {
				temp = p[(int)((double)(rand() + 1) / (RAND_MAX + 2)*(N+1))];
				for (j = 0; j < 4; j++) {
					ret = ans[0] + ans[1] + ans[2] + ans[3];
					ret += temp - ans[j];
					energy = M - ret;
					if (M < ret)energy += 100000000;

					if (energy < energy_min) {
						energy_min = energy;
						ans[j] = temp;
					}
					else if ((double)(rand() + 1) / (RAND_MAX + 2) < exp((energy_min - energy) / T*10)) {
						energy_min = energy;
						ans[j] = temp;
					}
				}

			}
		}
		ret=ans[0]+ +ans[1] + ans[2] + ans[3];
		printf("%d\n", ret);
	}
    return 0;
}

C++: #include<iostream>//JOI 2007 ??¬??? 3??????
using namespace std;
int max_p[200000001];
int p[1001];
int main ()
{
	long n,m;
	long i,j;
	int r;
	while(cin >> n >> m,n)
	{
		for(i=0;i<=m;i++)
		{
			max_p[i]=0;
		}
		for(i=0;i<n;i++)
		{
			cin >> p[i];
		}
		max_p[0]=1;
		for(i=0;i<m;i++)
		{
			if(max_p[i]>=1 && max_p[i]<5)
			{
				r=max_p[i];
				for(j=0;j<n;j++)
				{
					if(i+p[j]<=m)
					{
						if(max_p[i+p[j]]==0 || r+1<max_p[i+p[j]])
						{
							max_p[i+p[j]]=r+1;
						}
					}
				}
			}
		}
		for(i=m;i>=0;i--)
		{
			if(max_p[i]!=0)
			{
				cout <<  i << endl;
				break;
			}
		}
	}
	return 0;
}