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Lines changed: 29 additions & 0 deletions

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	`1`	`+package main`
	`2`	`+`
	`3`	`+typeTreeNodestruct {`
	`4`	`+Valint`
	`5`	`+Left*TreeNode`
	`6`	`+Right*TreeNode`
	`7`	`+}`
	`8`	`+`
	`9`	`+/**`
	`10`	`+因为给定的树是BST，所以可以知道如果采用后续遍历的方式，第一个找到的节点应该是最大的节点。所以采用递归的方式从最大的节点开始改变树的值`
	`11`	`+*/`
	`12`	`+varsumint`
	`13`	`+`
	`14`	`+funcconvertBST(rootTreeNode)TreeNode {`
	`15`	`+sum=0`
	`16`	`+helper(root)`
	`17`	`+returnroot`
	`18`	`+}`
	`19`	`+`
	`20`	`+funchelper(root*TreeNode) {`
	`21`	`+ifroot==nil {`
	`22`	`+return`
	`23`	`+}`
	`24`	`+helper(root.Right)`
	`25`	`+`
	`26`	`+root.Val+=sum`
	`27`	`+sum=root.Val`
	`28`	`+helper(root.Left)`
	`29`	`+}`

Lines changed: 18 additions & 0 deletions

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	`1`	`+package main`
	`2`	`+`
	`3`	`+/**`
	`4`	`+定义两个标志位，单调递增和单调递减`
	`5`	`+扫描一遍，判断是否递增或者递减`
	`6`	`+*/`
	`7`	`+funcisMonotonic(A []int)bool {`
	`8`	`+increasing,decreasing:=true,true`
	`9`	`+fori:=1;i<len(A);i++ {`
	`10`	`+ifA[i]>A[i-1] {`
	`11`	`+decreasing=false`
	`12`	`+}`
	`13`	`+ifA[i]<A[i-1] {`
	`14`	`+increasing=false`
	`15`	`+}`
	`16`	`+}`
	`17`	`+returnincreasing\|\|decreasing`
	`18`	`+}`

Lines changed: 59 additions & 0 deletions

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	`1`	`+package main`
	`2`	`+`
	`3`	`+/**`
	`4`	`+遍历一遍，先判断左边是不是符合规则`
	`5`	`+再判断右边`
	`6`	`+注意，如果有相等的元素，那一定是在两个部分的中间`
	`7`	`+*/`
	`8`	`+funcvalidMountainArray(A []int)bool {`
	`9`	`+iflen(A)<3 {`
	`10`	`+returnfalse`
	`11`	`+}`
	`12`	`+i:=0`
	`13`	`+l:=len(A)`
	`14`	`+fori+1<l&&A[i]<A[i+1] {`
	`15`	`+i++`
	`16`	`+}`
	`17`	`+ifi==0\|\|i==l-1 {`
	`18`	`+returnfalse`
	`19`	`+}`
	`20`	`+fori+1<l&&A[i]>A[i+1] {`
	`21`	`+i++`
	`22`	`+}`
	`23`	`+returni==l-1`
	`24`	`+}`
	`25`	`+`
	`26`	`+/**`
	`27`	`+由于上面的速度太慢，于是找到了最快的AC如下：`
	`28`	`+先找到最大的（就是中间的元素）`
	`29`	`+`
	`30`	`+*/`
	`31`	`+funcvalidMountainArray1(a []int)bool {`
	`32`	`+iflen(a)<3 {`
	`33`	`+returnfalse`
	`34`	`+}`
	`35`	`+max:=0`
	`36`	`+index:=0`
	`37`	`+fori,v:=rangea {`
	`38`	`+ifv>max {`
	`39`	`+max=v`
	`40`	`+index=i`
	`41`	`+}`
	`42`	`+}`
	`43`	`+ifindex==0\|\|index==len(a)-1 {`
	`44`	`+returnfalse`
	`45`	`+}`
	`46`	`+fori,j:=0,1;i<=index&&j<=index;i,j=i+1,j+1 {`
	`47`	`+ifa[i]>=a[j] {`
	`48`	`+returnfalse`
	`49`	`+}`
	`50`	`+}`
	`51`	`+`
	`52`	`+fori,j:=index,index+1;i<len(a)&&j<len(a);i,j=i+1,j+1 {`
	`53`	`+ifa[i]<=a[j] {`
	`54`	`+returnfalse`
	`55`	`+}`
	`56`	`+}`
	`57`	`+returntrue`
	`58`	`+`
	`59`	`+}`

Lines changed: 30 additions & 0 deletions

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	`1`	`+package main`
	`2`	`+`
	`3`	`+/**`
	`4`	`+先计算数组中所有偶数的和`
	`5`	`+遍历操作`
	`6`	`+如果之前是偶数，从和中减去`
	`7`	`+执行加操作`
	`8`	`+如果之后是偶数，再加到和里`
	`9`	`+*/`
	`10`	`+funcsumEvenAfterQueries(A []int,queries [][]int) []int {`
	`11`	`+`
	`12`	`+sum:=0`
	`13`	`+for_,v:=rangeA {`
	`14`	`+ifv%2==0 {`
	`15`	`+sum+=v`
	`16`	`+}`
	`17`	`+}`
	`18`	`+ret:= []int{}`
	`19`	`+for_,v:=rangequeries {`
	`20`	`+ifA[v[0]]%2==0 {`
	`21`	`+sum-=A[v[0]]`
	`22`	`+}`
	`23`	`+A[v[0]]+=v[1]`
	`24`	`+ifA[v[0]]%2==0 {`
	`25`	`+sum+=A[v[0]]`
	`26`	`+}`
	`27`	`+ret=append(ret,sum)`
	`28`	`+}`
	`29`	`+returnret`
	`30`	`+}`

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