题解 | #输出二叉树的右视图#

package main

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 * 求二叉树的右视图
 * @param xianxu int整型一维数组 先序遍历
 * @param zhongxu int整型一维数组 中序遍历
 * @return int整型一维数组
*/
func solve(xianxu []int, zhongxu []int) []int {
	ma := make(map[int]int)
	for i,val := range zhongxu{
		ma[val] = i 
	}
	return doSolve(xianxu,0,ma,make([]int,0),0,len(zhongxu)-1,0)
	// write code here
}

func doSolve(pre[]int,curP int,ma map[int]int,res[]int,st int ,en int ,curLen int)[]int{
	if st > en {
		return res
	}
	root := pre[curP]
	if curLen >= len(res) {
		res = append(res,root)
	}
	mid := ma[root]
	res = doSolve(pre,curP+1+mid-st,ma,res,mid+1,en,curLen+1)
	res = doSolve(pre,curP+1,ma,res,st,mid-1,curLen+1)
	return res
}