Create 1345-jump-game-iv.js

Author: everthis

1345-jump-game-iv.js

@@ -0,0 +1,45 @@
+/**
+ * @param {number[]} arr
+ * @return {number}
+ */
+var minJumps = function (arr) {
+  if (arr.length === 1) return 0
+  const n = arr.length
+  const indexMap = new Map()
+  for (let i = n - 1; i >= 0; i--) {
+    if (!indexMap.has(arr[i])) {
+      indexMap.set(arr[i], [])
+    }
+    indexMap.get(arr[i]).push(i)
+  }
+  let distance = 0
+  const queue = [0, null]
+  const visited = new Set([0])
+  while (queue.length > 0) {
+    const index = queue.shift()
+    if (index !== null) {
+      if (index > 0 && !visited.has(index - 1)) {
+        visited.add(index - 1)
+        queue.push(index - 1)
+      }
+      if (index < n - 1 && !visited.has(index + 1)) {
+        if (index + 1 === n - 1) return distance + 1
+        visited.add(index + 1)
+        queue.push(index + 1)
+      }
+      for (const nb of indexMap.get(arr[index])) {
+        if (!visited.has(nb) && nb !== index - 1 && nb !== index + 1) {
+          if (nb === n - 1) return distance + 1
+          visited.add(nb)
+          queue.push(nb)
+        }
+      }
+    } else {
+      distance++
+      if (queue.length > 0) {
+        queue.push(null)
+      }
+    }
+  }
+  return -1
+}