Minimize Malware Spread II LeetCode solution in JavaScript

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var minMalwareSpread = function (graph, initial) {
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  let n = graph.length;
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  let AdjList = new Map();
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  let listFromGraph = (mat) => {
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    // convert adj matrix to adj list
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    for (let i = 0; i < n; i++) {
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      AdjList[i] = [];
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      for (let j = 0; j < n; j++) {
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        if (mat[i][j] === 1 && i !== j) {
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          AdjList[i].push(j);
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        }
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      }
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    }
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  };
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  listFromGraph(graph);
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  let visitedSet = new Set(); //visited set, to manage the visited nodes & their count as they are unique
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  let dfs = (curr, node) => {
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    // dfs helper, visit the graph assuming that node, given as 2nd parameter is deleted
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    if (curr === node) {
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      return;
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    }
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    if (visitedSet.has(curr)) {
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      return;
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    }
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    visitedSet.add(curr); // size of visited shows how many nodes are visited/affected by the malware
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    let neighbours = AdjList[curr];
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    for (let i in neighbours) {
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      // visit all the neighbours
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      dfs(neighbours[i], node);
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    }
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  };
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  let MinSpread = n; // min index of node with max reduction in malware
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  let SpreadDist = n; // number of nodes affected by malware if MinSpread was deleted
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  for (let i = 0; i < initial.length; i++) {
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    for (let j = 0; j < initial.length; j++) {
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      // find the total nodes affected if ith node is removed
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      dfs(initial[j], initial[i]);
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    }
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    if (SpreadDist == visitedSet.size) {
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      // to get min index but same impact
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      MinSpread = Math.min(initial[i], MinSpread);
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    }
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    if (SpreadDist > visitedSet.size) {
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      // to get max impact
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      MinSpread = initial[i];
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      SpreadDist = visitedSet.size;
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    }
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    visitedSet.clear(); // clear visited set for next index to be deleted
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  }
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  return MinSpread;
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};