Submission #493262

#	Time	Username	Problem	Language	Result	Execution time	Memory
493262		HaYoungJoon	Knapsack (NOI18_knapsack)	C++14	100 / 100	83 ms	3036 KiB

knapsack

#include <bits/stdc++.h>
#define ll long long

using namespace std;

ll dp[2001];

typedef pair<ll,ll> pii;
vector<pii > pre[2001],items;

bool cmp(pii A, pii B) {
    return A.first > B.first;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    int n,S;
    cin >> S >> n;
    ll v,k,w;
    for (int i = 1; i <= n; i++) {
        cin >> v >> w >> k;
        pre[w].push_back({v,k});
    }
    items.push_back({0,0});
    for (int w = 1; w <= S; w++) {
        if (pre[w].empty()) continue;
        sort(pre[w].begin(),pre[w].end(),cmp);
        ll weight = S;
        for (int i = 0; i < pre[w].size() && weight > 0; i++) {
            for (int j = 1; j <= pre[w][i].second && weight > 0; j++) {
                weight -= w;
                if (weight < 0) break;
                items.push_back({w,pre[w][i].first});
            }
        }
    }
    for (int i = 1; i < items.size(); i++)
        for (int j = S; j >= 0; j--)
            if (j - items[i].first >= 0) dp[j] = max(dp[j],dp[j - items[i].first ] + items[i].second);
    ll res = 0;
    for (int i = 1; i <= S; i++) res = max(res,dp[i]);
    cout << res;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:30:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         for (int i = 0; i < pre[w].size() && weight > 0; i++) {
      |                         ~~^~~~~~~~~~~~~~~
knapsack.cpp:38:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for (int i = 1; i < items.size(); i++)
      |                     ~~^~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 27 / 27