✨ [1971] bfs

Author: enkr1

1971/gpt_solution.js

@@ -0,0 +1,66 @@
+function validPath(n, edges, source, destination) {
+  // Step 1: Build adjacency list
+  let graph = buildGraph(n, edges);
+  console.log("graph")
+  console.log(graph)
+
+
+  // Step 2: Initialize BFS
+  let queue = [];
+  queue.push(source);
+
+  // Step 3: Initialize visited array
+  let visited = Array(n).fill(false);
+
+  // console.log("visited")
+  // console.log(visited)
+
+  visited[source] = true; // this is how the duplicated was prevented.
+
+  // Step 4: Perform BFS
+  while (queue.length > 0) {
+    let currentVertex = queue.shift();
+    console.log("currentVertex: " + currentVertex)
+
+
+    // Step 4.1: Check if destination is reached
+    if (currentVertex === destination) {
+      console.log(`> Found ${currentVertex} === ${destination}`)
+      return true;
+    }
+
+    console.log("graph[currentVertex]: " + graph[currentVertex])
+
+    // Step 4.2: Iterate through adjacent vertices
+    for (let neighbor of graph[currentVertex]) {
+      if (!visited[neighbor]) {
+        visited[neighbor] = true;
+        queue.push(neighbor);
+      }
+    }
+  }
+
+  // Step 5: No valid path found
+  return false;
+}
+
+function buildGraph(n, edges) {
+  // const graph = new Array(n).fill(null).map(() => []);
+  const graph = Array.from({ length: n }, () => []);
+  // console.log("init")
+  // console.log(graph)
+
+  for (const [u, v] of edges) {
+    graph[u].push(v);
+    graph[v].push(u);
+  }
+
+  return graph;
+}
+
+// let x = validPath(3, [[0, 1], [1, 2], [2, 0]], 0, 2)
+// let x = validPath(6, [[0, 1], [0, 2], [3, 5], [5, 4], [4, 3]], 0, 5)
+// let x = validPath(1, [], 0, 0)
+let x = validPath(10, [[4, 3], [1, 4], [4, 8], [1, 7], [6, 4], [4, 2], [7, 4], [4, 0], [0, 9], [5, 4]], 5, 9)
+console.log("x")
+console.log(x)

1971/my_solution.js

@@ -0,0 +1,47 @@
+// 1971. Find if Path Exists in Graph
+/**
+ * @param {number} n
+ * @param {number[][]} edges
+ * @param {number} source
+ * @param {number} destination
+ * @return {boolean}
+ */
+const validPath = (n, e, s, d) => {
+  let map = new Map();
+
+  for (let i = 0; i < e.length; i++) {
+    // console.log("e[i]")
+    // console.log(e[i])
+    // console.log(map.get(e[i][0]) || []);
+    // console.log((map.get(e[i][1]) || []).push(e[i][0]));
+
+
+    map.set(e[i][0], (map.get(e[i][0]) || []).concat(e[i][1]));
+    map.set(e[i][1], (map.get(e[i][1]) || []).concat(e[i][0]));
+    // console.log(map)
+  }
+  console.log(map)
+
+  const findInLayer = (list, count) => {
+    console.log("> Proc")
+    console.log(list, count)
+    if (count === n || 0 === list.length) return false;
+
+    if (list.includes(d)) return true;
+
+    for (let i = 0; i < list.length; i++) {
+      console.log()
+      count++;
+      return findInLayer(map.get(list[i]), 0);
+    }
+  }
+
+  return (undefined === map.get(s)) ? true : findInLayer(map.get(s), 0);
+};
+
+// let x = validPath(3, [[0, 1], [1, 2], [2, 0]], 0, 2)
+// let x = validPath(6, [[0, 1], [0, 2], [3, 5], [5, 4], [4, 3]], 0, 5)
+// let x = validPath(1, [], 0, 0)
+let x = validPath(10, [[4, 3], [1, 4], [4, 8], [1, 7], [6, 4], [4, 2], [7, 4], [4, 0], [0, 9], [5, 4]], 5, 9)
+console.log("x")
+console.log(x)

1971/solution.js

@@ -0,0 +1,27 @@
+// 1971. Find if Path Exists in Graph
+/**
+ * @param {number} n
+ * @param {number[][]} edges
+ * @param {number} source
+ * @param {number} destination
+ * @return {boolean}
+ */
+const validPath = (n, e, s, d) => {
+  let map = new Map();
+
+  for (let i = 0; i < e.length; i++) {
+    map.set(e[i][0], (map.get(e[i][0]) || []).concat(e[i][1]));
+    map.set(e[i][1], (map.get(e[i][1]) || []).concat(e[i][0]));
+  }
+
+  const findInLayer = (list, count) => {
+    if (count === n || 0 === list.length) return false;
+    if (list.includes(d)) return true;
+
+    for (let i = 0; i < list.length; i++) {
+      return findInLayer(map.get(list[i]), count + 1);
+    }
+  }
+
+  return (undefined === map.get(s)) ? true : findInLayer(map.get(s), 0);
+};