tst2.cpp

void DFS(vector<pair<int, int>> graph[], int src, int prev_len, int *max_len,
         vector<bool> &visited) {
    visited[src] = 1;
    int curr_len = 0;
    pair<int, int> adjacent;

    for (int i = 0; i < graph[src].size(); i++) {
        adjacent = graph[src][i];

        if (!visited[adjacent.first]) {
            curr_len = prev_len + adjacent.second;
            DFS(graph, adjacent.first, curr_len, max_len, visited);
        }

        if ((*max_len) < curr_len)
            *max_len = curr_len;

        curr_len = 0;
    }
}

int longestCable(vector<pair<int, int>> graph[], int n) {
    int max_len = INT_MIN;

    for (int i = 1; i <= n; i++) {
        vector<bool> visited(n + 1, false);
        DFS(graph, i, 0, &max_len, visited);
    }

    return max_len;
}