Submission #1039332

#	Time	Username	Problem	Language	Result	Execution time	Memory
1039332		fimh	Split the sequence (APIO14_sequence)	C++14	71 / 100	71 ms	8556 KiB

sequence

#include <bits/stdc++.h>
using ll = long long;
// #define int long long
#define fi first
#define pll pair<ll, ll>
#define se second
#define isz(x) (int)(x).size()
#define sq(x) (ll)(x)*(x)
using namespace std;

const ll inf = 1e18;
const int mod = 1e9 + 7;
const int maxn = 1e4 + 5;
const int block = 500;

int mid;
ll best, cost;
int ps[maxn], trace[maxn][201];
ll dp[maxn][2];

void compute(int j, int l, int r, int optl, int optr){
    if (l > r) return;
    mid = (l + r) >> 1; best = inf;
    for (int i = optl; i <= min(mid, optr); ++i){
        cost = sq(ps[mid] - ps[i - 1]);
        if (best >= dp[i - 1][0] + cost){
            best = dp[i - 1][0] + cost;
            trace[mid][j] = i;
        }
    }
    dp[mid][1] = best;
    compute(j, l, mid - 1, optl, trace[mid][j]);
    compute(j, mid + 1, r, trace[mid][j], optr);
}

void test(){
    int n, k; cin >> n >> k;
    for (int i = 1; i <= n; ++i){
        cin >> ps[i]; ps[i] += ps[i - 1];
        dp[i][0] = sq(ps[i]);
    }
    for (int j = 2; j <= k + 1; ++j){
        compute(j, 1, n, 1, n);
        for (int i = 1; i <= n; ++i) dp[i][0] = dp[i][1];
    }
    ll ans = (sq(ps[n]) - dp[n][0]) / 2; cout << ans << "\n";
    vector<int> path;
    int y = k + 1, x = trace[n][y];
    while (y > 1){
        path.push_back(x - 1); --y;
        x = trace[x - 1][y];
    }
    reverse(path.begin(), path.end());
    for (int i : path) cout << i << " ";
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    test();
}

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