添加新题目

二叉树/路径总和III/main.go

@@ -0,0 +1,41 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func main() {
+
+}
+func pathSum(root *TreeNode, targetSum int) int {
+	if root == nil {
+		return 0
+	}
+	if root.Left == nil && root.Right == nil && root.Val == targetSum {
+		return 1
+	}
+	hash := make(map[int]int)
+	var culcalute func(root *TreeNode, hash map[int]int, total int, targetSum int) int
+	culcalute = func(roottmp *TreeNode, hash map[int]int, total int, targetSum int) int {
+		if roottmp == nil {
+			return 0
+		}
+		restmp := 0
+		hashtmp := make(map[int]int)
+		for k, v := range hash {
+			hashtmp[k] = v
+		}
+		totalnum := total + roottmp.Val
+		if value, ok := hash[totalnum-targetSum]; ok {
+			restmp = restmp + value
+		}
+		hashtmp[totalnum]++
+		res := culcalute(roottmp.Left, hashtmp, totalnum, targetSum) + culcalute(roottmp.Right, hashtmp, totalnum, targetSum) + restmp
+		return res
+	}
+	hash[0]++
+	result := culcalute(root, hash, 0, targetSum)
+	return result
+}