Merge pull request #735 from openset/develop

Add: Path Sum

Author: Shuo

internal/leetcode/problems_status.go

@@ -21,6 +21,7 @@ var problemStatus = map[int]bool{
 	18:   true,
 	20:   true,
 	21:   true,
+	22:   true,
 	24:   true,
 	26:   true,
 	27:   true,
@@ -45,6 +46,7 @@ var problemStatus = map[int]bool{
 	104:  true,
 	108:  true,
 	110:  true,
+	112:  true,
 	118:  true,
 	119:  true,
 	121:  true,
@@ -111,6 +113,7 @@ var problemStatus = map[int]bool{
 	443:  true,
 	445:  true,
 	448:  true,
+	455:  true,
 	459:  true,
 	461:  true,
 	468:  true,
@@ -174,6 +177,7 @@ var problemStatus = map[int]bool{
 	896:  true,
 	905:  true,
 	908:  true,
+	912:  true,
 	914:  true,
 	917:  true,
 	922:  true,
@@ -218,9 +222,11 @@ var problemStatus = map[int]bool{
 	1046: true,
 	1047: true,
 	1051: true,
+	1071: true,
 	1108: true,
 	1154: true,
 	1163: true,
+	1170: true,
 	1185: true,
 	1189: true,
 	1221: true,

problems/path-sum/path_sum.go

@@ -1 +1,24 @@
 package problem112
+
+import "github.com/openset/leetcode/internal/kit"
+
+// TreeNode - Definition for a binary tree node.
+type TreeNode = kit.TreeNode
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func hasPathSum(root *TreeNode, sum int) bool {
+	if root == nil {
+		return false
+	}
+	if root.Left == nil && root.Right == nil {
+		return root.Val == sum
+	}
+	return hasPathSum(root.Left, sum-root.Val) || hasPathSum(root.Right, sum-root.Val)
+}

problems/path-sum/path_sum_test.go

@@ -1 +1,34 @@
 package problem112
+
+import (
+	"testing"
+
+	"github.com/openset/leetcode/internal/kit"
+)
+
+type testType struct {
+	in   []int
+	sum  int
+	want bool
+}
+
+func TestHasPathSum(t *testing.T) {
+	tests := [...]testType{
+		{
+			in:   []int{5, 4, 8, 11, kit.NULL, 13, 4, 7, 2, kit.NULL, kit.NULL, kit.NULL, 1},
+			sum:  22,
+			want: true,
+		},
+		{
+			in:   []int{5, 8, 4, 4, 13, kit.NULL, 11, 7, 2},
+			sum:  22,
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		got := hasPathSum(kit.SliceInt2TreeNode(tt.in), tt.sum)
+		if got != tt.want {
+			t.Fatalf("in: %v, got: %v, want: %v", tt.in, got, tt.want)
+		}
+	}
+}