46.ts 全排列, 回溯算法

Author: tbswang

46.ts

@@ -5,38 +5,55 @@
  */
 
 // @lc code=start
+// function permute(nums: number[]): number[][] {
+//   const result: number[][] = []
+//   // 路径
+//   // const track 
+//   // 选择列表
+//   // const list
+//   function backtrack(track: number[], list: number[]) {
+//     // 终结条件
+//     if (list.length === 0) {
+//       result.push([...track])
+//       return
+//     }
+//     // 选择列表
+//     for (let i = 0; i < list.length; i++) {
+//       if (track.indexOf(list[i]) > -1) {
+//         /** 如果已经选择过 */
+//         continue
+//       }
+//       const ele = list[i]
+//       track.push(ele)
+//       list.splice(i, 1)
+//       backtrack(track, list)
+//       track.pop()
+//       list.splice(i, 0, ele)
+//     }
+//   }
+
+//   backtrack([], nums)
+//   return result
+// };
+//  记录选择列表
 function permute(nums: number[]): number[][] {
-  const result: number[][] = []
-  // 路径
-  // const track 
-  // 选择列表
-  // const list
-  function backtrack(track: number[], list: number[]) {
-    // 终结条件
-    if (list.length === 0) {
-      result.push([...track])
-      return
-    }
-    // 选择列表
-    for (let i = 0; i < list.length; i++) {
-      if (track.indexOf(list[i]) > -1) {
-        /** 如果已经选择过 */
-        continue
-      }
-      const ele = list[i]
-      track.push(ele)
-      list.splice(i, 1)
-      backtrack(track, list)
-      track.pop()
-      list.splice(i, 0, ele)
+  const res = []
+  function backtrack(track: number[], options: number[]){
+    if(options.length === 0){
+      res.push(track)
     }
+    options.map(o => {
+      backtrack(track.concat(o), options.filter(i => i!== o))
+    })
   }
 
   backtrack([], nums)
-  return result
-};
+  return res
+}
+
 // @lc code=end
 
 
-const nums = [1, 2, 3]
+// const nums = [1, 2, 3]
+const nums = [0]
 console.log(permute(nums))