[20251207] BOJ / P3 / 건초 더미 / 권혁준

Author: oncsr

khj20006/202512/07 BOJ P3 건초 더미.md

@@ -0,0 +1,76 @@
+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+using ll = long long;
+
+int N, Q;
+vector<pair<int, int>> infos;
+int arr[300001]{}, idx[300001]{}, cnt[300001]{}, ans[300000]{};
+ll sum[300001]{};
+vector<tuple<int, int, int>> queries;
+
+void upt(int x, int v) {
+	for (; x <= 300000; x += x & -x) {
+		sum[x] += v;
+		cnt[x]++;
+	}
+}
+
+pair<ll, int> find(int x) {
+	pair<ll, int> ret = { 0,0 };
+	for (; x > 0; x -= x & -x) {
+		ret.first += sum[x];
+		ret.second += cnt[x];
+	}
+	return ret;
+}
+
+int main() {
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin >> N >> Q;
+	for (int i = 1; i <= N; i++) {
+		cin >> arr[i];
+		infos.emplace_back(arr[i], i);
+	}
+
+	sort(infos.begin(), infos.end());
+	for (int i = 0; i < N; i++) {
+		auto [v, x] = infos[i];
+		idx[x] = i + 1;
+	}
+
+	queries.resize(Q);
+	for (int i = 0; i < Q; i++) {
+		auto& [X, P, x] = queries[i];
+		cin >> X >> P;
+		x = i;
+	}
+
+	sort(queries.begin(), queries.end());
+
+	int pos = 0;
+	for (auto [X, P, x] : queries) {
+		while (pos < X) {
+			pos++;
+			upt(idx[pos], arr[pos]);
+		}
+		pair<ll, int> ri = find(N);
+		if (P > ri.first) {
+			ans[x] = -1;
+			continue;
+		}
+		int s = 0, e = N - 1, m = (s + e + 1) >> 1;
+		while (s < e) {
+			pair<ll, int> le = find(m);
+			if (ri.first - le.first >= P) s = m;
+			else e = m - 1;
+			m = (s + e + 1) >> 1;
+		}
+		ans[x] = ri.second - find(m).second;
+	}
+
+	for (int i = 0; i < Q; i++) cout << ans[i] << '\n';
+
+}
+```