Submission #717810

#	Time	Username	Problem	Language	Result	Execution time	Memory
717810		Toxtaq	Split the sequence (APIO14_sequence)	C++17	0 / 100	2069 ms	8892 KiB

sequence

#include<bits/stdc++.h>
using namespace std;
vector<long long>pref, v;
int n, k;
long long cost(int i, int j){
    long long L = pref[j] - pref[i - 1], R = pref[n] - pref[j];
    return L * R;
}
long long rec(int l, int k){
    long long res = 0;
    if(l > n)return -1e18;
    if(l == n || k == 0)return 0;
    for(int i = l;i <= n;++i){
        res = max(res, cost(l, i) + rec(i + 1, k - 1));
    }
    return res;
}
int main()
{
    cin >> n >> k;
    pref.resize(n + 1);
    v.resize(n + 1);
    for(int i = 1;i <= n;++i){
        cin >> v[i];
        pref[i] = pref[i - 1] + v[i];
    }
    vector<vector<long long>>dp(k + 1, vector<long long>(n + 1, -1e18));
    vector<vector<pair<int, int>>>par(k + 1, vector<pair<int, int>>(n + 1, {-1, -1}));
    for(int i = 1;i <= n;++i)dp[0][i] = 0;
    for(int i = 1;i <= k;++i)dp[k][n] = 0;
    for(int K = 1;K <= k;++K){
        for(int i = n;i >= 1;--i){
            for(int j = i;j < n;++j){
                long long num = cost(i, j) + dp[K - 1][j + 1];
                if(dp[K][i] < num){
                    dp[K][i] = num;
                    par[K][i] = {K - 1, j + 1};
                }
//                cout << "dp[" << K << "][" << i << "]=" << dp[K][i] << ": {" << par[K][i].first << ", " << par[K][i].second << "}\n";
            }
        }
    }
    long long mx = -1e18;
    pair<int, int>num;
    for(int i = 1;i <= n;++i){
        if(mx < dp[k][i]){
            mx = dp[k][i];
            num = {k, i};
        }
    }
    vector<int>ans;
    while(num.first > 0){
        ans.push_back(num.second);
        num = par[num.first][num.second];
    }
    cout << mx << '\n';
    for(int i : ans)cout << i << " ";
//    cout << mx << '\n' << rec(1, k);
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29