Submission #683305

#	Time	Username	Problem	Language	Result	Execution time	Memory
683305		vjudge1	Knapsack (NOI18_knapsack)	C++17	100 / 100	132 ms	10340 KiB

knapsack

#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define pb push_back
#define gcd __gcd
#define task "1e5 + 5"
using namespace std;
const int N = 1e5 + 5;
int s, n, dp[2005];
vector<int> a[2005], W, V;
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen(task".inp", "r", stdin);
    //freopen(task".out", "w", stdout);
    cin >> s >> n;
    for(int i = 1; i <= n; i++){
        int v, w, k; cin >> v >> w >> k;
        int pow2 = 1;
        while(k >= pow2 && pow2 * w <= s){
            a[pow2 * w].pb(pow2 * v);
            k -= pow2, pow2 *= 2;
        }
        if(k > 0 && k * w <= s){
            a[k * w].pb(k * v);
        }
    }
    for(int i = 1; i <= s; i++){
        sort(a[i].begin(), a[i].end(), [](int x, int y){return x > y;});
        while(!a[i].empty() && s / i < a[i].size()) a[i].pop_back();
        for(int x : a[i]){
            W.pb(i);
            V.pb(x);
        }
    }
    int ans = 0;
    for(int i = 0; i < W.size(); i++){
        for(int j = s; j >= W[i]; j--){
            dp[j] = max(dp[j], dp[j - W[i]] + V[i]);
            ans = max(ans, dp[j]);
        }
    }
    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:30:38: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         while(!a[i].empty() && s / i < a[i].size()) a[i].pop_back();
      |                                ~~~~~~^~~~~~~~~~~~~
knapsack.cpp:37:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for(int i = 0; i < W.size(); i++){
      |                    ~~^~~~~~~~~~

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