穷举所有叶子节点,判断是否满足条件。
package main import "fmt" type TreeNode struct { Val int Left *TreeNode Right *TreeNode } func demo(root *TreeNode, sum int, path []int, result *[][]int) { if root.Left != nil { demo(root.Left, sum-root.Val, append(path, root.Val), result) } if root.Right != nil { demo(root.Right, sum-root.Val, append(path, root.Val), result) } // 为叶子节点,递归结束。判断 root.Val == sum if root.Left == nil && root.Right == nil && root.Val == sum { // 由于闭包的原因,在root.Val==A的时候,A的右子节点递归与A的左子节点递归传递的path是同一个引用地址。 // *result = append(*result, append(path, sum)) tmp := make([]int, len(path)+1) copy(tmp, append(path, sum)) *result = append(*result, tmp) } } func pathSum(root *TreeNode, sum int) [][]int { if root == nil { return nil } result := make([][]int, 0) path := make([]int, 0) demo(root, sum, path, &result) fmt.Println(result) return result } func main() { //node := TreeNode{1, &TreeNode{2, nil, nil}, nil} node := TreeNode{1, nil, nil} sum := pathSum(&node, 1) fmt.Println(sum) }