Submission #989922

#	Time	Username	Problem	Language	Result	Execution time	Memory
989922		awf	Split the sequence (APIO14_sequence)	C++14	100 / 100	856 ms	83804 KiB

sequence

#include<bits/stdc++.h>
using namespace std;
 
const int N = 1e5 + 15;
int tv[N][205];
#define int long long
 
int a[N];
int n, k;
int dp[N][2];
int pre[N];
// int tv[N][205];
int id = 1;
 
int cost(int l, int r) {
    return (pre[r] - pre[l-1]) * (pre[n] - pre[r]);
}
 
void cal(int k, int l, int r, int opl, int opr) {
    if (l > r) return;
    int mid = (l + r) / 2;
    int opm = -1;
    dp[mid][1] = -1e18; 
    for (int i = min(mid,opr); i >= opl; i--) {
        int val = dp[i-1][0] + cost(i, mid);
        if (val > dp[mid][1]){
            dp[mid][1] = val;
            opm = i;
        }
    }
    tv[mid][id] = opm;
    cal(k, l, mid - 1, opl, opm);
    cal(k, mid + 1, r, opm, opr);
}
 
signed main() {
    ios_base::sync_with_stdio();
    cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
    
    for (int i = 1; i <= n; i++) {
        pre[i] = pre[i-1] + a[i];
    }
 
    for (int i = 1; i <= n; i++) dp[i][0] = cost(1, i);
 
    for (int i = 2; i <= k; i++) {
        id++;
        cal(i, i, n, i-1, n);
        for (int j = 1; j <= n; j++) {
            dp[j][0] = dp[j][1];
            dp[j][1] = 0;
        }
    }
 
    int mx = -1e18; 
    int last = 0;
    for (int i = 1; i <= n; i++) {
    	// cout << dp[i][0] << endl;
        if (mx < dp[i][0]) {
            last = i;
            mx = dp[i][0];
        }
    }
    cout << mx << endl;
    for (int i = k; i >= 1; i--) {
        cout << last << " ";
        last = tv[last][i]-1;
    }
}

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