Submission #1148626

#	Time	Username	Problem	Language	Result	Execution time	Memory
1148626		blackslex	Split the sequence (APIO14_sequence)	C++20	50 / 100	2094 ms	24644 KiB

sequence

#include<bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<ll, ll>;

int n, k;

int main() {
    scanf("%d %d", &n, &k);
    vector<int> a(n + 5), pref(n + 5);
    vector<vector<ll>> dp(k + 5, vector<ll>(n + 5));
    vector<vector<int>> par(k + 5, vector<int>(n + 5));
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
        pref[i] = pref[i - 1] + a[i];
    }
    auto get = [&] (int l, int r) {
        return pref[r] - pref[l - 1];
    };
    for (int i = 1; i < n; i++) {
        dp[1][i] = 1LL * get(1, i) * get(i + 1, n);
        par[1][i] = i;
    }
    for (int i = 2; i <= k; i++) {
        for (int j = 2; j < n; j++) {
            for (int l = 1; l < j; l++) {
                ll nval = dp[i - 1][l] + 1LL * get(l + 1, j) * get(j + 1, n);
                if (nval >= dp[i][j]) {
                    dp[i][j] = nval;
                    par[i][j] = l;
                }
            }
        }
    }
    pii xx = {0, 0};
    for (int i = 1; i < n; i++) xx = max(xx, {dp[k][i], i});
    vector<pii> u{{k, xx.second}};
    while (u.back().first != 1) {
        auto [x, y] = u.back();
        u.emplace_back(x - 1, par[x][y]);
    }
    reverse(u.begin(), u.end());
    printf("%lld\n", xx.first);
    for (auto &[x, y]: u) printf("%d ", y);
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:45:36: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::tuple_element<1, std::pair<long long int, long long int> >::type' {aka 'long long int'} [-Wformat=]
   45 |     for (auto &[x, y]: u) printf("%d ", y);
      |                                   ~^    ~
      |                                    |    |
      |                                    int  std::tuple_element<1, std::pair<long long int, long long int> >::type {aka long long int}
      |                                   %lld
sequence.cpp:10:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |     scanf("%d %d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |         scanf("%d", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~

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