Update with graph approach. Add spaces after control flow statements.

Author: aadil42

javascript/1443-minimum-time-to-collect-all-apples-in-a-tree.js

@@ -1,5 +1,5 @@
 /**
- * DFS 
+ * Graph | DFS 
  * Time O(n) | Space O(n)
  * https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree/
  * @param {number} n
@@ -8,40 +8,41 @@
  * @return {number}
  */
 var minTime = function(n, edges, hasApple) {
-    
-    if(n === 1) return 0;
+    if (n === 1) return 0;
+    const result = dfs(0, -1, makeGraph(edges), hasApple) - 2;
+    return (result > 0 && result) || 0;
+};
 
-    const tree = {};
+const dfs = (curr, pre, graph, hasApple) => {
+    let pathLen = 0;
+    for (const nextNode of graph[curr]) {
+        if (nextNode === pre) continue;
+        pathLen += dfs(nextNode, curr, graph, hasApple);
+    }   
 
-    for(let i = 0; i < edges.length; i++) {
+    if (pathLen > 0 || hasApple[curr]) return pathLen+2;
+    return 0;
+}
 
-        const parent = edges[i][0];
-        const child = edges[i][1];
+const makeGraph = (edges) => {
+    const graph = {};
 
-        if(!tree[parent]) {
-            tree[parent] = [];
-        }
-
-        if(!tree[child]) {
-            tree[child] = [];
-        };
+    for (let i = 0; i < edges.length; i++) {
 
-        tree[child].push(parent);
-        tree[parent].push(child);
-    }
+        const from = edges[i][0];
+        const to = edges[i][1];
 
-    const dfs = (curr, pre) => {
+        if (!graph[from]) {
+            graph[from] = [];
+        }
 
-        let pathLen = 0;
-        for(const nextNode of tree[curr]) {
-            if(nextNode === pre) continue;
-            pathLen += dfs(nextNode, curr);
-        }   
+        if (!graph[to]) {
+            graph[to] = [];
+        };
 
-        if(pathLen > 0 || hasApple[curr]) return pathLen+2;
-        return 0;
+        graph[to].push(from);
+        graph[from].push(to);
     }
 
-    const result = dfs(0, -1) - 2;
-    return (result > 0 && result) || 0;
-};
+    return graph;
+}