Submission #666457

#	Time	Username	Problem	Language	Result	Execution time	Memory
666457		hoanghq2004	Feast (NOI19_feast)	C++14	100 / 100	120 ms	10524 KiB

feast

#include <bits/stdc++.h>
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

const int N = 3e5 + 10;

int n, k;
long long s[N];
pair <long long, int> f[N];

int calc(long long C) {
    pair <long long, int> opt = {0, 0};
    for (int i = 1; i <= n; ++i) {
        f[i].first = opt.first + s[i] - C;
        f[i].second = opt.second - 1;
        if (f[i] < f[i - 1]) f[i] = f[i - 1];
        if (make_pair(f[i].first - s[i], f[i].second) > opt)
            opt = make_pair(f[i].first - s[i], f[i].second);
    }
    return - f[n].second;
}

int main() {
    ios :: sync_with_stdio(0); cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; ++i) {
        cin >> s[i];
        s[i] += s[i - 1];
    }
    if (calc(0) <= k) {
        cout << f[n].first << '\n';
        exit(0);
    }
    long long L = 0, R = 1e14;
    while (L < R) {
        long long mid = L + R >> 1;
        if (calc(mid) <= k) R = mid;
        else L = mid + 1;
    }
    calc(L);
    cout << f[n].first + 1LL * k * L << '\n';
}

Compilation message (stderr)

feast.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("O3")
      | 
feast.cpp:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization ("unroll-loops")
      | 
feast.cpp: In function 'int main()':
feast.cpp:44:27: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   44 |         long long mid = L + R >> 1;
      |                         ~~^~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29