时间线(Timeline G) 题解

思路分析

按题目要求使用对应数据结构与算法模拟/递推求解，注意数据范围边界与时间复杂度。

参考代码

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, c;
    long long m;
    if (!(cin >> n >> m >> c)) return 0;
    vector<long long> dp(n + 1);
    for (int i = 1; i <= n; ++i) cin >> dp[i];
    vector<vector<pair<int, long long>>> adj(n + 1);
    vector<int> indeg(n + 1, 0);
    for (int i = 0; i < c; ++i) {
        int a, b;
        long long x;
        cin >> a >> b >> x;
        adj[a].push_back({b, x});
        indeg[b]++;
    }
    vector<int> q;
    q.reserve(n);
    for (int i = 1; i <= n; ++i) {
        if (indeg[i] == 0) q.push_back(i);
    }
    for (size_t head = 0; head < q.size(); ++head) {
        int u = q[head];
        for (auto& edge : adj[u]) {
            int v = edge.first;
            long long w = edge.second;
            dp[v] = max(dp[v], dp[u] + w);
            if (--indeg[v] == 0) q.push_back(v);
        }
    }
    for (int i = 1; i <= n; ++i) {
        cout << dp[i] << "\n";
    }
    return 0;
}