Update README.md

Author: yanglbme

lcof2/剑指 Offer II 109. 开密码锁/README.md

@@ -236,6 +236,47 @@ public:
 };
 ```
 
+#### Go
+
+```go
+func openLock(deadends []string, target string) int {
+	dead := map[string]bool{}
+	for _, s := range deadends {
+		dead[s] = true
+	}
+	if dead["0000"] {
+		return -1
+	}
+	if target == "0000" {
+		return 0
+	}
+	q := []string{"0000"}
+	visited := map[string]bool{"0000": true}
+	step := 0
+	for len(q) > 0 {
+		step++
+		size := len(q)
+		for i := 0; i < size; i++ {
+			cur := q[0]
+			q = q[1:]
+			for j := 0; j < 4; j++ {
+				for k := -1; k <= 1; k += 2 {
+					next := cur[:j] + string((cur[j]-'0'+byte(k)+10)%10+'0') + cur[j+1:]
+					if next == target {
+						return step
+					}
+					if !dead[next] && !visited[next] {
+						q = append(q, next)
+						visited[next] = true
+					}
+				}
+			}
+		}
+	}
+	return -1
+}
+```
+
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