diff --git a/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest.go b/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest.go
new file mode 100644
index 00000000..ff43f2b4
--- /dev/null
+++ b/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest.go	
@@ -0,0 +1,14 @@
+package leetcode
+
+func numRabbits(ans []int) int {
+	total, m := 0, make(map[int]int)
+	for _, v := range ans {
+		if m[v] == 0 {
+			m[v] += v
+			total += v + 1
+		} else {
+			m[v]--
+		}
+	}
+	return total
+}
diff --git a/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest_test.go b/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest_test.go
new file mode 100644
index 00000000..f8c8bed1
--- /dev/null
+++ b/Algorithms/0781. Rabbits in Forest/781. Rabbits in Forest_test.go	
@@ -0,0 +1,51 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question781 struct {
+	para781
+	ans781
+}
+
+// para 是参数
+// one 代表第一个参数
+type para781 struct {
+	one []int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans781 struct {
+	one int
+}
+
+func Test_Problem781(t *testing.T) {
+
+	qs := []question781{
+		question781{
+			para781{[]int{1, 1, 2}},
+			ans781{5},
+		},
+
+		question781{
+			para781{[]int{10, 10, 10}},
+			ans781{11},
+		},
+
+		question781{
+			para781{[]int{}},
+			ans781{0},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 781------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans781, q.para781
+		fmt.Printf("【input】:%v       【output】:%v\n", p, numRabbits(p.one))
+	}
+	fmt.Printf("\n\n\n")
+}