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121 changes: 121 additions & 0 deletions problems/0112.路径总和.md
Original file line number Diff line number Diff line change
Expand Up @@ -766,11 +766,132 @@ let pathSum = function(root, targetSum) {
};
```

## TypeScript

> 0112.路径总和

**递归法:**

```typescript
function hasPathSum(root: TreeNode | null, targetSum: number): boolean {
function recur(node: TreeNode, sum: number): boolean {
console.log(sum);
if (
node.left === null &&
node.right === null &&
sum === 0
) return true;
if (node.left !== null) {
sum -= node.left.val;
if (recur(node.left, sum) === true) return true;
sum += node.left.val;
}
if (node.right !== null) {
sum -= node.right.val;
if (recur(node.right, sum) === true) return true;
sum += node.right.val;
}
return false;
}
if (root === null) return false;
return recur(root, targetSum - root.val);
};
```

**递归法(精简版):**

```typescript
function hasPathSum(root: TreeNode | null, targetSum: number): boolean {
if (root === null) return false;
targetSum -= root.val;
if (
root.left === null &&
root.right === null &&
targetSum === 0
) return true;
return hasPathSum(root.left, targetSum) ||
hasPathSum(root.right, targetSum);
};
```

**迭代法:**

```typescript
function hasPathSum(root: TreeNode | null, targetSum: number): boolean {
type Pair = {
node: TreeNode, // 当前节点
sum: number // 根节点到当前节点的路径数值总和
}

const helperStack: Pair[] = [];
if (root !== null) helperStack.push({ node: root, sum: root.val });
let tempPair: Pair;
while (helperStack.length > 0) {
tempPair = helperStack.pop()!;
if (
tempPair.node.left === null &&
tempPair.node.right === null &&
tempPair.sum === targetSum
) return true;
if (tempPair.node.right !== null) {
helperStack.push({
node: tempPair.node.right,
sum: tempPair.sum + tempPair.node.right.val
});
}
if (tempPair.node.left !== null) {
helperStack.push({
node: tempPair.node.left,
sum: tempPair.sum + tempPair.node.left.val
});
}
}
return false;
};
```

> 0112.路径总和 ii

**递归法:**

```typescript
function pathSum(root: TreeNode | null, targetSum: number): number[][] {
function recur(node: TreeNode, sumGap: number, routeArr: number[]): void {
if (
node.left === null &&
node.right === null &&
sumGap === 0
) resArr.push([...routeArr]);
if (node.left !== null) {
sumGap -= node.left.val;
routeArr.push(node.left.val);
recur(node.left, sumGap, routeArr);
sumGap += node.left.val;
routeArr.pop();
}
if (node.right !== null) {
sumGap -= node.right.val;
routeArr.push(node.right.val);
recur(node.right, sumGap, routeArr);
sumGap += node.right.val;
routeArr.pop();
}
}
const resArr: number[][] = [];
if (root === null) return resArr;
const routeArr: number[] = [];
routeArr.push(root.val);
recur(root, targetSum - root.val, routeArr);
return resArr;
};
```

## Swift

0112.路径总和

**递归**

```swift
func hasPathSum(_ root: TreeNode?, _ targetSum: Int) -> Bool {
guard let root = root else {
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