131分割字符串更清楚的typescript版本

Author: pzppzz

problems/0131.分割回文串.md

@@ -454,31 +454,36 @@ var partition = function(s) {
 
 ```typescript
 function partition(s: string): string[][] {
-    function isPalindromeStr(s: string, left: number, right: number): boolean {
-        while (left < right) {
-            if (s[left++] !== s[right--]) {
-                return false;
+    const res: string[][] = []
+    const path: string[] = []
+    const isHuiwen = (
+        str: string, 
+        startIndex: number, 
+        endIndex: number
+        ): boolean => {
+        for (; startIndex < endIndex; startIndex++, endIndex--) {
+            if (str[startIndex] !== str[endIndex]) {
+                return false
             }
         }
-        return true;
+        return true
     }
-    function backTracking(s: string, startIndex: number, route: string[]): void {
-        let length: number = s.length;
-        if (length === startIndex) {
-            resArr.push(route.slice());
-            return;
+    const rec = (str: string, index: number): void => {
+        if (index >= str.length) {
+            res.push([...path])
+            return
         }
-        for (let i = startIndex; i < length; i++) {
-            if (isPalindromeStr(s, startIndex, i)) {
-                route.push(s.slice(startIndex, i + 1));
-                backTracking(s, i + 1, route);
-                route.pop();
+        for (let i = index; i < str.length; i++) {
+            if (!isHuiwen(str, index, i)) {
+               continue
             }
+            path.push(str.substring(index, i + 1))
+            rec(str, i + 1)
+            path.pop()
         }
     }
-    const resArr: string[][] = [];
-    backTracking(s, 0, []);
-    return resArr;
+    rec(s, 0)
+    return res
 };
 ```