gistfile1.txt

class Solution {
public:
    vector<vector<int>> modifiedGraphEdges(int n, vector<vector<int>>& edges, int source, int destination, int target) {
        vector<vector<pair<int, int>>> graph(n);
        for (int i = 0; i < edges.size(); i++) {
            graph[edges[i][0]].push_back({ edges[i][1], i });
            graph[edges[i][1]].push_back({ edges[i][0], i });
        }

        vector<int> route;
        long long max = dijkstra(graph, edges, source, destination, 2000000000, route);
        if (max < target) {
            return {};
        }
        bool first = true;
        for (;;) {
            long long min = dijkstra(graph, edges, source, destination, 1, route);
            if (min > target) {
                return {};
            }
            if (min == target) {
                for (auto v : route) {
                    if (edges[v][2] == -1) {
                        edges[v][2] = 1;
                    }
                }
                return edges;
            }
            int last = -1;
            for (auto v : route) {
                if (edges[v][2] == -1) {
                    last = v;
                    break;
                }
            }
            if (first) {
                first = false;
                set<int> s(route.begin(), route.end());
                for (int i = 0; i < edges.size() ;i++){
                    auto& v = edges[i];
                    if (v[2] == -1 && s.find(i) == s.end()) {
                        v[2] = 2000000000;
                    }
                }
            }
            
            edges[last][2] = target - min + 1;
        }
    }

    long long dijkstra(vector<vector<pair<int, int>>>& graph, vector<vector<int>>& edges, int source, int destination, int def, vector<int>& route) {
        int n = graph.size();
        vector<long long> depth(n, -1);
        vector<int> prev(n);
        vector<int> edge(n, -1), visited(n);

        priority_queue<pair<long long, int>> pq;

        depth[source] = 0;
        prev[source] = -1;
        pq.push({ 0, source });

        while (pq.size() > 0) {
            auto el = pq.top();
            pq.pop();

            if (visited[el.second]) {
                continue;
            }
            if (el.second == destination) {
                route.clear();
                int v = destination;
                while (v != source) {
                    route.push_back(edge[v]);
                    v = prev[v];
                }
                return depth[el.second];
            }
            visited[el.second] = 1;
            auto cur = depth[el.second];
            for (auto e : graph[el.second]) {
                auto ch = e.first;
                auto id = e.second;
                auto v = edges[id][2];
                if (v == -1) {
                    v = def;
                }
                if (depth[ch] >= 0 && depth[ch] <= cur + v) {
                    continue;
                }
                depth[ch] = cur + v;
                prev[ch] = el.second;
                edge[ch] = id;
                pq.push({ -depth[ch], ch });
            }
        }
        
        return 2000000000;
    }
};