diff --git a/problems/0134.加油站.md b/problems/0134.加油站.md index dfed2d96..9b660ea0 100644 --- a/problems/0134.加油站.md +++ b/problems/0134.加油站.md @@ -240,6 +240,25 @@ class Solution: ``` Go: +```go +func canCompleteCircuit(gas []int, cost []int) int { + curSum := 0 + totalSum := 0 + start := 0 + for i := 0; i < len(gas); i++ { + curSum += gas[i] - cost[i] + totalSum += gas[i] - cost[i] + if curSum < 0 { + start = i+1 + curSum = 0 + } + } + if totalSum < 0 { + return -1 + } + return start +} +``` Javascript: ```Javascript diff --git a/problems/0235.二叉搜索树的最近公共祖先.md b/problems/0235.二叉搜索树的最近公共祖先.md index 15ff7af4..d78db42a 100644 --- a/problems/0235.二叉搜索树的最近公共祖先.md +++ b/problems/0235.二叉搜索树的最近公共祖先.md @@ -265,6 +265,54 @@ class Solution: else: return root ``` Go: +> BSL法 + +```go +/** + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode + * } + */ +//利用BSL的性质(前序遍历有序) +func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode { + if root==nil{return nil} + if root.Val>p.Val&&root.Val>q.Val{//当前节点的值大于给定的值,则说明满足条件的在左边 + return lowestCommonAncestor(root.Left,p,q) + }else if root.Val 普通法 + +```go +/** + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode + * } + */ +//递归会将值层层返回 +func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode { + //终止条件 + if root==nil||root.Val==p.Val||root.Val==q.Val{return root}//最后为空或者找到一个值时,就返回这个值 + //后序遍历 + findLeft:=lowestCommonAncestor(root.Left,p,q) + findRight:=lowestCommonAncestor(root.Right,p,q) + //处理单层逻辑 + if findLeft!=nil&&findRight!=nil{return root}//说明在root节点的两边 + if findLeft==nil{//左边没找到,就说明在右边找到了 + return findRight + }else {return findLeft} +} +``` + diff --git a/problems/0501.二叉搜索树中的众数.md b/problems/0501.二叉搜索树中的众数.md index dfd589ce..3ca7d892 100644 --- a/problems/0501.二叉搜索树中的众数.md +++ b/problems/0501.二叉搜索树中的众数.md @@ -428,7 +428,100 @@ class Solution: return self.res ``` Go: +暴力法(非BSL) +```go +/** + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode + * } + */ +func findMode(root *TreeNode) []int { + var history map[int]int + var maxValue int + var maxIndex int + var result []int + history=make(map[int]int) + traversal(root,history) + for k,value:=range history{ + if value>maxValue{ + maxValue=value + maxIndex=k + } + } + for k,value:=range history{ + if value==history[maxIndex]{ + result=append(result,k) + } + } + return result +} +func traversal(root *TreeNode,history map[int]int){ + if root.Left!=nil{ + traversal(root.Left,history) + } + if value,ok:=history[root.Val];ok{ + history[root.Val]=value+1 + }else{ + history[root.Val]=1 + } + if root.Right!=nil{ + traversal(root.Right,history) + } +} +``` + +计数法BSL(此代码在执行代码里能执行,但提交后报错,不知为何,思路是对的) + +```go +/** + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode + * } + */ + var count,maxCount int //统计计数 +func findMode(root *TreeNode) []int { + var result []int + var pre *TreeNode //前指针 + if root.Left==nil&&root.Right==nil{ + result=append(result,root.Val) + return result + } + traversal(root,&result,pre) + return result +} +func traversal(root *TreeNode,result *[]int,pre *TreeNode){//遍历统计 + //如果BSL中序遍历相邻的两个节点值相同,则统计频率;如果不相同,依据BSL中序遍历排好序的性质,重新计数 + if pre==nil{ + count=1 + }else if pre.Val==root.Val{ + count++ + }else { + count=1 + } + //如果统计的频率等于最大频率,则加入结果集;如果统计的频率大于最大频率,更新最大频率且重新将结果加入新的结果集中 + if count==maxCount{ + *result=append(*result,root.Val) + }else if count>maxCount{ + maxCount=count//重新赋值maxCount + *result=[]int{}//清空result中的内容 + *result=append(*result,root.Val) + } + pre=root//保存上一个的节点 + if root.Left!=nil{ + traversal(root.Left,result,pre) + } + if root.Right!=nil{ + traversal(root.Right,result,pre) + } +} +``` diff --git a/problems/1005.K次取反后最大化的数组和.md b/problems/1005.K次取反后最大化的数组和.md index 387de147..c3e99f7e 100644 --- a/problems/1005.K次取反后最大化的数组和.md +++ b/problems/1005.K次取反后最大化的数组和.md @@ -138,6 +138,30 @@ class Solution: ``` Go: +```Go +func largestSumAfterKNegations(nums []int, K int) int { + sort.Slice(nums, func(i, j int) bool { + return math.Abs(float64(nums[i])) > math.Abs(float64(nums[j])) + }) + + for i := 0; i < len(nums); i++ { + if K > 0 && nums[i] < 0 { + nums[i] = -nums[i] + K-- + } + } + + if K%2 == 1 { + nums[len(nums)-1] = -nums[len(nums)-1] + } + + result := 0 + for i := 0; i < len(nums); i++ { + result += nums[i] + } + return result +} +``` Javascript: