Submission #782457

#	Time	Username	Problem	Language	Result	Execution time	Memory
782457		amukkalir	Knapsack (NOI18_knapsack)	C++17	100 / 100	378 ms	198884 KiB

knapsack

#include<bits/stdc++.h>
using namespace std;
#define ioss ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
//#define int long long
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
int t, n;
vector<pii> v[2004];
vector<pii> items;
bool comp(pii a, pii b) {
    return (a.fi > b.fi);
}
int dp[25004][2004];
int ks(int idx, int weight) {
    if(idx == items.size()) return 0;
    if(weight <= 0) return 0;
    if(dp[idx][weight] != -1) return dp[idx][weight];

    int ret = ks(idx+1, weight);
    if(weight-items[idx].se >= 0) ret = max(ret, ks(idx+1, weight-items[idx].se)+items[idx].fi);
    return dp[idx][weight] = ret;
}
signed main() {
    ioss;
    memset(dp, -1, sizeof(dp));
    cin >> t >> n;
    for(int i = 1; i <= n; i++) {
        int l, e, k; cin >> l >> e >> k;
        v[e].pb({l, min(t/e, k)});
    }
    for(int i = 1; i <= t; i++) sort(v[i].begin(), v[i].end(), comp);
    for(int i = 1; i <= t; i++) {
        int tmp = 0;
        for(auto [val, cnt] : v[i]) {
            for(int j = 1; j <= cnt; j++) {
                if(tmp+i <= t) items.pb({val, i}), tmp += i;
                else break;
            }
        }
    }
    int ans = ks(0, t);
    cout << ans << endl;
}

/*
2000 + 2000/2 + 2000/3 + ...

*/

Compilation message (stderr)

knapsack.cpp: In function 'int ks(int, int)':
knapsack.cpp:17:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     if(idx == items.size()) return 0;
      |        ~~~~^~~~~~~~~~~~~~~

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