Merge pull request doocs#230 from ElectricBubble/master

Add Solution.go for 0067.Add Binary

Author: yanglbme

solution/0067.Add Binary/Solution.go

@@ -0,0 +1,24 @@
+func addBinary(a string, b string) string {
+	for len(a) > len(b) {
+		b = "0" + b
+	}
+	for len(a) < len(b) {
+		a = "0" + a
+	}
+	zero := []byte("0")[0]
+	ret := make([]byte, len(a))
+	for right := len(a) - 1; right > 0; right-- {
+		t := ret[right] + a[right] + b[right] - zero*2
+		ret[right] = t%2 + zero
+		if t >= 2 {
+			ret[right-1] = 1
+		}
+	}
+	t := ret[0] + a[0] + b[0] - zero*2
+	ret[0] = t%2 + zero
+	if t >= 2 {
+		ret = append([]byte("1"), ret...)
+	}
+
+	return string(ret)
+}