Submission #286519

#	Time	Username	Problem	Language	Result	Execution time	Memory
286519		BeanZ	Split the sequence (APIO14_sequence)	C++14	100 / 100	1836 ms	83192 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'

const int N = 1e5 + 5;
ll dp[N][2];
int opt[N][205];
int a[N];
void DP(int k, int l, int r, int optl, int optr){
        if (l > r) return;
        int mid = (l + r) >> 1;
        dp[mid][1] = -1e18;
        int best = optl;
        for (int i = optl; i <= min(mid - 1, optr); i++){
                if (dp[mid][1] <= (dp[i][0] + 1ll * a[i] * (a[mid] - a[i]))){
                        dp[mid][1] = dp[i][0] + 1ll * a[i] * (a[mid] - a[i]);
                        best = i;
                        opt[mid][k] = i;
                }
        }
        DP(k, l, mid - 1, optl, best);
        DP(k, mid + 1, r, best, optr);
}
int main(){
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        if (fopen("VietCT.INP", "r")){
                freopen("VietCT.INP", "r", stdin);
                freopen("VietCT.OUT", "w", stdout);
        }
        int n, k;
        cin >> n >> k;
        for (int i = 1; i <= n; i++) cin >> a[i], a[i] = a[i] + a[i - 1];
        for (int i = 1; i <= k; i++){
                DP(i, 1, n, 1, n);
                for (int j = 1; j <= n; j++){
                        dp[j][0] = dp[j][1];
                }
        }
        cout << dp[n][1] << endl;
        for (int i = k; i >= 1; i--){
                cout << opt[n][i] << " ";
                n = opt[n][i];
        }
}
/*
7 3
4 1 3 4 0 2 3
*/

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:31:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   31 |                 freopen("VietCT.INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:32:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   32 |                 freopen("VietCT.OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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