update

Author: sunkafei

XCPC模板合集.pdf

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+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <iostream>
+#include <algorithm>
+#include <climits>
+#include <vector>
+#include <queue>
+using namespace std;
+template<typename T, int maxsize> struct ModifiablePriorityQueue { // 大根堆
+	int data[maxsize * 2];
+	int pos[maxsize * 2];
+	T value[maxsize * 2];
+	int sz;
+	ModifiablePriorityQueue() : pos(), sz(0) {}
+	void up(int i) { // 值变大
+		auto index = data[i];
+		auto val = value[index];
+		while (i > 1) {
+			int fa = i / 2;
+			if (val > value[data[fa]]) {
+				data[i] = data[fa];
+				pos[data[i]] = i;
+				i = fa;
+			}
+			else {
+				break;
+			}
+		}
+		data[i] = index;
+		pos[index] = i;
+	}
+	void down(int i) { // 值变小
+		auto index = data[i];
+		auto val = value[index];
+		while (i * 2 <= sz) {
+			int child = i * 2;
+			if (i * 2 + 1 <= sz && value[data[i * 2 + 1]] > value[data[child]]) {
+				child = i * 2 + 1;
+			}
+			if (val < value[data[child]]) {
+				data[i] = data[child];
+				pos[data[i]] = i;
+				i = child;
+			}
+			else {
+				break;
+			}
+		}
+		data[i] = index;
+		pos[index] = i;
+	}
+	void push(int index, const T& val) {
+		sz += 1;
+		data[sz] = index;
+		value[index] = val;
+		up(sz);
+	}
+	void pop() {
+		pos[data[1]] = 0;
+		data[1] = data[sz];
+		sz -= 1;
+		if (sz > 0) {
+			down(1);
+		}
+	}
+	void erase(int index) {
+		index = pos[index];
+		pos[data[index]] = 0;
+		data[index] = data[sz];
+		sz -= 1;
+		if (index <= sz) {
+			down(index);
+		}
+	}
+	void modify(int index, const T& val) {
+		if (pos[index] == 0) {
+			push(index, val);
+		}
+		else if (val > value[index]) {
+			value[index] = val;
+			up(pos[index]);
+		}
+		else {
+			value[index] = val;
+			down(pos[index]);
+		}
+	}
+	int top() const {
+		return data[1];
+	}
+	T get(int index) const {
+		return value[index];
+	}
+	T maximum() const {
+		return value[data[1]];
+	}
+	bool contains(int index) const {
+		return pos[index] != 0;
+	}
+	int size() const {
+		return sz;
+	}
+	bool empty() const {
+		return sz == 0;
+	}
+};
+int main() { // 洛谷 P4779
+	static int d[210000];
+	static vector<pair<int, int>> G[210000];
+	int n, m, s;
+	scanf("%d %d %d", &n, &m, &s);
+	for (int i = 0; i < m; ++i) {
+		int x, y, z;
+		scanf("%d %d %d", &x, &y, &z);
+		G[x].emplace_back(y, z);
+	}
+	static ModifiablePriorityQueue<int, 210000> Q;
+	memset(d, 0x3f, sizeof(d));
+	d[s] = 0;
+	Q.push(s, 0);
+	while (!Q.empty()) {
+		auto x = Q.top(); Q.pop();
+		for (auto [y, w] : G[x]) {
+			if (d[y] > d[x] + w) {
+				d[y] = d[x] + w;
+				Q.modify(y, -d[y]);
+			}
+		}
+	}
+	for (int i = 1; i <= n; ++i) {
+		printf("%d ", d[i] == 0x3f3f3f3f ? INT_MAX : d[i]);
+	}
+	printf("\n");
+	return 0;
+}