A: Destination City

Author: Shuo

problems/destination-city/destination_city.go

@@ -0,0 +1,14 @@
+package problem1436
+
+func destCity(paths [][]string) string {
+	m := make(map[string]bool)
+	for _, path := range paths {
+		m[path[0]] = true
+	}
+	for _, path := range paths {
+		if !m[path[1]] {
+			return path[1]
+		}
+	}
+	return ""
+}

problems/destination-city/destination_city_test.go

@@ -0,0 +1,41 @@
+package problem1436
+
+import "testing"
+
+type testType struct {
+	in   [][]string
+	want string
+}
+
+func TestDestCity(t *testing.T) {
+	tests := [...]testType{
+		{
+			in: [][]string{
+				{"London", "New York"},
+				{"New York", "Lima"},
+				{"Lima", "Sao Paulo"},
+			},
+			want: "Sao Paulo",
+		},
+		{
+			in: [][]string{
+				{"B", "C"},
+				{"D", "B"},
+				{"C", "A"},
+			},
+			want: "A",
+		},
+		{
+			in: [][]string{
+				{"A", "Z"},
+			},
+			want: "Z",
+		},
+	}
+	for _, tt := range tests {
+		got := destCity(tt.in)
+		if got != tt.want {
+			t.Fatalf("in: %v, got: %v, want: %v", tt.in, got, tt.want)
+		}
+	}
+}