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https://git.sb/baoshuo/OI-codes.git
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81 lines
1.5 KiB
C++
81 lines
1.5 KiB
C++
#include <iostream>
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#include <cmath>
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#include <functional>
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#include <queue>
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#include <utility>
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#include <vector>
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using std::cin;
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using std::cout;
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const char endl = '\n';
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const int N = 1e5 + 5;
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int n, m, p = 1, a[N], pre[N], suf[N], ans;
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bool vis[N];
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std::priority_queue<
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std::pair<int, int>,
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std::vector<std::pair<int, int>>,
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std::greater<>>
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q;
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int main() {
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std::ios::sync_with_stdio(false);
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cin.tie(nullptr);
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cin >> n >> m;
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for (int i = 1, x; i <= n; i++) {
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cin >> x;
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if (a[p] * x < 0) {
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a[++p] = x;
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} else {
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a[p] += x;
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}
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}
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int cnt = 0;
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for (int i = 1; i <= p; i++) {
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pre[i] = i - 1;
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suf[i] = i + 1;
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if (a[i] > 0) {
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ans += a[i];
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cnt++;
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}
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q.emplace(std::abs(a[i]), i);
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}
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while (cnt > m) {
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while (vis[q.top().second]) q.pop();
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auto o = q.top();
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q.pop();
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if (pre[o.second] != 0 && suf[o.second] != p + 1 || a[o.second] > 0) {
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cnt--;
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ans -= o.first;
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int l = pre[o.second],
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r = suf[o.second];
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a[o.second] += a[l] + a[r];
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q.emplace(std::abs(a[o.second]), o.second);
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pre[suf[l]] = pre[l];
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suf[pre[l]] = suf[l];
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vis[l] = true;
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pre[suf[r]] = pre[r];
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suf[pre[r]] = suf[r];
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vis[r] = true;
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}
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}
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cout << ans << endl;
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return 0;
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}
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