1192.js

var criticalConnections = function(n, connections) {
    var g = [], low = Array(n), res = [];
    low.fill(0);
    for (let con of connections) {
        g[con[0]] = g[con[0]] || [];
        g[con[1]] = g[con[1]] || [];
        g[con[0]].push(con[1]);
        g[con[1]].push(con[0]);
    }
    
    var dfs=function(cur, v, p) {
        var dfn = cur;
        low[v] = cur;
        for (let i of g[v]) {
            if (i != p) {
                if (low[i] == 0) {
                    cur++;
                    dfs(cur, i, v);
                    if (low[i] > dfn) {
                        res.push([i, v]);
                    }
                }
                low[v] = Math.min(low[v], low[i]);
            }
        }
    }
    dfs(1, 0, -1);
    return res;
};