Update index.ts

masx200 · masx200 · commit b4e03e59af28 · 2023-12-11T18:38:24.000+08:00
diff --git a/range-sum-query-mutable/index.ts b/range-sum-query-mutable/index.ts
@@ -33,8 +33,8 @@ export function build(
     pushup(node);
 }
 function pushdown(start: number, end: number, node: TreeNode) {
-    node.left = new TreeNode();
-    node.right = new TreeNode();
+    if (!node.left) node.left = new TreeNode();
+    if (!node.right) node.right = new TreeNode();
 }
 
 export function change(

Original file line number	Diff line number	Diff line change
`@@ -33,8 +33,8 @@ export function build(`
`33`	`33`	`pushup(node);`
`34`	`34`	`}`
`35`	`35`	`function pushdown(start: number, end: number, node: TreeNode) {`
`36`		`- node.left = new TreeNode();`
`37`		`- node.right = new TreeNode();`
	`36`	`+ if (!node.left) node.left = new TreeNode();`
	`37`	`+ if (!node.right) node.right = new TreeNode();`
`38`	`38`	`}`
`39`	`39`
`40`	`40`	`export function change(`