update: 112. 路径总和 && 路径总和-ii js迭代法

This commit is contained in:
mengyuan
2021-11-22 20:18:58 +08:00
parent e9d28fce57
commit 407c08457c

View File

@ -614,6 +614,7 @@ func haspathsum(root *treenode,sumnodes *[]int,targetsum int,result *[][]int){
0112.路径总和
**递归**
```javascript
/**
* @param {treenode} root
@ -643,9 +644,38 @@ let haspathsum = function (root, targetsum) {
// return haspathsum(root.left, targetsum - root.val) || haspathsum(root.right, targetsum - root.val);
};
```
**迭代**
```javascript
let hasPathSum = function(root, targetSum) {
if(root === null) return false;
let nodeArr = [root];
let valArr = [0];
while(nodeArr.length) {
let curNode = nodeArr.shift();
let curVal = valArr.shift();
curVal += curNode.val;
// 为叶子结点且和等于目标数返回true
if (curNode.left === null && curNode.right === null && curVal === targetSum) {
return true;
}
// 左节点,将当前的数值也对应记录下来
if (curNode.left) {
nodeArr.push(curNode.left);
valArr.push(curVal);
}
// 右节点,将当前的数值也对应记录下来
if (curNode.right) {
nodeArr.push(curNode.right);
valArr.push(curVal);
}
}
return false;
};
```
0113.路径总和-ii
**递归**
```javascript
let pathsum = function (root, targetsum) {
// 递归法
@ -677,7 +707,7 @@ let pathsum = function (root, targetsum) {
return res;
};
```
113 路径总和 精简版
**递归 精简版**
```javascript
var pathsum = function(root, targetsum) {
//递归方法
@ -701,6 +731,41 @@ var pathsum = function(root, targetsum) {
return resPath;
};
```
**迭代**
```javascript
let pathSum = function(root, targetSum) {
if(root === null) return [];
let nodeArr = [root];
let resArr = []; // 记录符合目标和的返回路径
let tempArr = [[]]; // 对应路径
let countArr = [0]; //对应和
while(nodeArr.length) {
let curNode = nodeArr.shift();
let curVal = countArr.shift();
let curNodeArr = tempArr.shift();
curVal += curNode.val;
curNodeArr.push(curNode.val);
// 为叶子结点且和等于目标数将此次结果数组push进返回数组中
if (curNode.left === null && curNode.right === null && curVal === targetSum) {
resArr.push(curNodeArr);
}
// 左节点,将当前的和及对应路径也对应记录下来
if (curNode.left) {
nodeArr.push(curNode.left);
countArr.push(curVal);
tempArr.push([...curNodeArr]);
}
// 右节点,将当前的和及对应路径也对应记录下来
if (curNode.right) {
nodeArr.push(curNode.right);
countArr.push(curVal);
tempArr.push([...curNodeArr]);
}
}
return resArr;
};
```