HDU-3466-Proud Merchants

#include <iostream>
#include <memory.h>
#include <vector>
#include <map>
#include <algorithm>
#include <cstdio>
#include <math.h>

using namespace std;

typedef long long LL;

const int MAXN = 5e2 + 10;
const int MAXM = 5e3 + 10;

struct Node
{
    int _p, _q, _v;
    bool operator < (const Node & that) const{
        return this->_q - this->_p < that._q - that._p;
    }
}node[MAXN];

int dp[MAXM];

int main()
{
    int n, m;
    while (~scanf("%d%d", &n, &m))
    {
        memset(dp, 0, sizeof(dp));
        for (int i = 1;i <= n;i++)
            scanf("%d%d%d", &node[i]._p, &node[i]._q, &node[i]._v);
        sort(node + 1, node + 1 + n);

        for (int i = 1;i <= n;i++)
        {
            for (int j = m;j >= node[i]._q;j--)
                dp[j] = max(dp[j], dp[j - node[i]._p] + node[i]._v);
        }

        printf("%d\n", dp[m]);
    }

    return 0;
}