/** * Definition for a binary tree node. * type TreeNode struct { *     Val int *     Left *TreeNode *     Right *TreeNode * } */func isBalanced(root *TreeNode) bool {   if root==nil{       return true   }     l:=height(root.Left)   r:=height(root.Right)   if l>r+1 || l+1       return false   }   return isBalanced(root.Left)&&isBalanced(root.Right)}
func height(root*TreeNode)int{    if root==nil{        return 0    }    l:=height(root.Left)    r:=height(root.Right)    if l>r{        return l+1    }    return r+1}

package main
import (  "fmt"  "time")
func main() {  c := make(chan bool)  go testSelectFor(c)
  c <- true  c <- false  close(c)
  time.Sleep(time.Duration(2) * time.Second)  fmt.Println("Hello, 世界")}
func testSelectFor(chExit chan bool) {  for {    select {    case v, ok := <-chExit:      if !ok {        fmt.Println("close channel 1", v)        break      }
      fmt.Println("ch2 val =", v)    }
  }
  fmt.Println("exit testSelectFor")}