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

import (
	"fmt"
	"sort"
)

func max(n, m int64) int64 {
	if n < m {
		return m
	} else {
		return n
	}
}

func main() {
	for {
		var N int
		var M int64
		fmt.Scan(&N, &M)
		if N == 0 && M == 0 {
			break
		}

		arr := make([]int64, N+1)
		for i := 1; i <= N; i++ {
			fmt.Scan(&arr[i])
		}
		sort.Slice(arr, func(i, j int) bool { return arr[i] < arr[j] })

		sums := make([]int64, len(arr)*len(arr))
		for i := 0; i < len(arr); i++ {
			for j := 0; j < len(arr); j++ {
				sums[i*len(arr)+j] = arr[i] + arr[j]
			}
		}

		sort.Slice(sums, func(i, j int) bool { return sums[i] < sums[j] })

		var m int64 = 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 <bits/stdc++.h>
using namespace std;
#define FOR(i, s, n) for(int i = s; i < (int)n; i++)
#define per(i, n) for(int i = n; i >= 0; i--)
#define ROF(i, s, n) for(int i = s; i >= (int)n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << "\n"
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define MP make_pair
#define EACH(i, n) for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define CLR(a) memset((a), 0 ,sizeof(a))
#define dump(x) cout << #x << " = " << (x) << "\n";
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << "\n";
#define sq(n) (n) * (n)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef priority_queue<int> maxpq;
typedef priority_queue< int, vector<int>, greater<int> > minpq;
static const double EPS = 1e-10;
static const double PI = acos( -1.0 );
static const int mod = 10007;
static const int INF = 1 << 25;
static const LL LL_INF = 1152921504606846976;
static const int dx[] = { 1, -1, 0,  0 };
static const int dy[] = { 0,  0, 1, -1 };

int n, m, ans;
VI ar;
int solve( int now, int d, int cnt ) {
	if ( cnt == 4 || now == n ) {
		return d;
	}
	int res = 0;
	for ( int i = 0; i + cnt <= 4 && d + ar[now] * i <= m; i++ ) {
		res = max( solve( now + 1, d + ar[ now ] * i, cnt + i ), res );
	}
	return res;
}
int main() {
	while ( ~scanf( "%d %d", &n, &m ) && n && m ) {
		ar.resize( n );
		for ( int i = 0; i < n; i++ ) {
			scanf( "%d", &ar[ i ] );
		}
		sort( ar.rbegin(), ar.rend() );
		ans = solve( 0, 0, 0 );
		printf( "%d\n", ans );
	}
	return 0;
}

C++: #include<stdio.h>
#include<algorithm>
using namespace std;
int i,j;
int main(void){
	int n,m;
	int data[1003];
	scanf("%d %d",&n,&m);
	while(n!=0 && m!=0){
		for(i=0;i<n;i++){
			scanf("%d",&data[i]);
		}
		data[n]=0;
		sort(data,data+n+1);
		/*for(i=0;i<=n;i++){
			printf("%d \n",data[i]);
		}*/
		int gou[500505];
		int cnt=0;
		for(i=0;i<=n;i++){
			for(j=i;j<=n;j++){
				gou[cnt]=data[i]+data[j];
				cnt++;
			}
		}
		sort(gou,gou+cnt);
		/*for(i=0;i<cnt;i++){
			printf("%d ",gou[i]);
		}
		printf("\n");*/
		//
		int max=0;
		for(i=0;i<cnt;i++){
			for(j=i;j<cnt;j++){
				if(m<gou[i]+gou[j]){
					break;
				}
				else if(max<gou[i]+gou[j]){
					max=gou[i]+gou[j];
				}
			}
		}
		printf("%d\n",max);
		scanf("%d %d",&n,&m);
	}
	return 0;
}

C++: #include<stdio.h>
#include<algorithm>
#include<set>
using namespace std;
int main(){
	int a,b,mato[1000];
	set<int> nums;
	while(scanf("%d%d",&a,&b),a,b){
		int res=0;
		for(int i=0;i<a;i++){scanf("%d",mato+i);}
		nums.clear();
		for(int i=0;i<=a;i++){
			for(int j=0;j<=a;j++){
				int r=0;
				if(i!=a)r+=mato[i];
				if(j!=a)r+=mato[j];
				nums.insert(r);
			}
		}
		set<int>::iterator it=nums.begin();
		while(it!=nums.end()){
			if(b-*it<0)break;
			set<int>::iterator itt=upper_bound(nums.begin(),nums.end(),b-*it);
			itt--;
			res=max(res,*it+*itt);
			it++;
		}
		printf("%d\n",res);
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
vector<long int> po;
long int n,a,low,m,lastans,memo[1005],ss;
void solve(int dp,long int sum);

int main(){
    while(1){
            ss=0;
        lastans=0;
        po.clear();
        low=100000000;
        for(int i=0;i<1005;i++)memo[i]=0;

        cin >> n >> m;
        if(n==0&&m==0)break;
        for(int i=0;i<n;i++){
            cin >> a;
            po.push_back(a);
            low=min(low,a);
        }
        solve(0,0);
        cout << lastans << endl;
        //cout <<"ss=" << ss << endl;
    }

    return 0;
}

void solve(int dp,long int sum){
    long int ans=0;
    ss++;
    //cout <<"ss=" << ss << endl;
    if(dp==n)return ;
    if(low+sum>m)return;
    if(memo[dp]>sum)return;
    else{
     memo[dp]=max(sum,memo[dp]);

     for(int i=0;i<n;i++){
        if(sum+po[i]<m){
            lastans=max(lastans,sum+po[i]);
            ans=max(ans,sum+po[i]);
            solve(dp+1,sum+po[i]);
            }
        }
    }
    return;
}

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 <vector>
#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
	int N, M, D;

	while (true)
	{
		scanf("%d", &N);
		scanf("%d", &M);

		if (N == 0 && M == 0) { break; }

		vector<int> C; C.push_back(0);

		for (int i = 0; i < N; i++)
		{
			scanf("%d", &D);

			if (D <= M)
			{
				C.push_back(D);
			}
		}

		vector<int> r1, r;

		for (int i = 0; i < C.size(); i++)
		{
			for (int j = i; j < C.size(); j++)
			{
				if (C[i] + C[j] <= M)
				{
					r1.push_back(C[i] + C[j]);
				}
			}
		}

		sort(r1.begin(), r1.end());

		r.push_back(r1[0]);

		for (int i = 0; i < r1.size(); i++)
		{
			if (r1[i - 1] != r1[i])
			{
				r.push_back(r1[i]);
			}
		}

		int ret = 0;

		for (int i = 0; i < r.size(); i++)
		{
			int ptr = upper_bound(r.begin(), r.end(), M - r[i]) - r.begin() - 1;
			
			if (ptr >= 0)
			{
				ret = max(ret, r[i] + r[ptr]);
			}
		}

		printf("%d\n", ret);
	}

	return 0;
}