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72 lines
2.0 KiB
C++
72 lines
2.0 KiB
C++
#include <iostream>
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#include <cstring>
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#include <queue>
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#include <vector>
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using std::cin;
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using std::cout;
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using std::endl;
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const int N = 100005;
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int n, m, x, h[N], nh[N];
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std::vector<std::pair<int, long long>> g[N];
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// Dijkstra - Shortest Path
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long long dist[N];
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bool vis[N];
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void dijkstra() {
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memset(dist, 0x3f, sizeof(dist));
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dist[1] = 0;
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std::priority_queue<std::pair<long long, int>, std::vector<std::pair<long long, int>>, std::greater<std::pair<long long, int>>> q;
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q.push(std::make_pair(0, 1));
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nh[1] = x;
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while (!q.empty()) {
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int u = q.top().second;
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q.pop();
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if (vis[u]) continue;
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vis[u] = true;
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for (auto e : g[u]) {
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int v = e.first;
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long long w = e.second;
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if (nh[u] - w > h[v]) { // 到达点的高度大于树顶高度
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if (dist[v] > dist[u] + nh[u] - h[v]) {
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dist[v] = dist[u] + nh[u] - h[v];
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nh[v] = h[v];
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q.push(std::make_pair(dist[v], v));
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}
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} else if (nh[u] - w < 0) { // 飞行中途会落地
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if (dist[v] > dist[u] + w - nh[u] + w) {
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dist[v] = dist[u] + w - nh[u] + w;
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nh[v] = 0;
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q.push(std::make_pair(dist[v], v));
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}
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} else if (dist[v] > dist[u] + w) { // 其他情况
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dist[v] = dist[u] + w;
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nh[v] = nh[u] - w;
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q.push(std::make_pair(dist[v], v));
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}
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}
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}
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}
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int main() {
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cin >> n >> m >> x;
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for (int i = 1; i <= n; i++) {
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cin >> h[i];
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}
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for (int i = 1; i <= m; i++) {
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int u, v;
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long long w;
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cin >> u >> v >> w;
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// 保证飞行中途不落地
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if (w <= h[u]) g[u].push_back(std::make_pair(v, w));
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if (w <= h[v]) g[v].push_back(std::make_pair(u, w));
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}
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dijkstra();
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cout << (dist[n] == 0x3f3f3f3f3f3f3f3f ? -1 : dist[n] + h[n] - nh[n]) << endl;
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return 0;
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}
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