Merge pull request #2355 from Freshield/master

新增：增加字符串章节 -> 替换数字的GO语言双指针实现

problems/kama54.替换数字.md

@@ -183,6 +183,54 @@ func main(){
     fmt.Printf(string(strByte))
 }
 ````
+Go使用双指针解法
+````go
+package main
+
+import "fmt"
+
+func replaceNumber(strByte []byte) string {
+	// 查看有多少字符
+	numCount, oldSize := 0, len(strByte)
+	for i := 0; i < len(strByte); i++ {
+		if (strByte[i] <= '9') && (strByte[i] >= '0') {
+			numCount ++
+		}
+	}
+	// 增加长度
+	for i := 0; i < numCount; i++ {
+		strByte = append(strByte, []byte("     ")...)
+	}
+	tmpBytes := []byte("number")
+	// 双指针从后遍历
+	leftP, rightP := oldSize-1, len(strByte)-1
+	for leftP < rightP {
+		rightShift := 1
+		// 如果是数字则加入number
+		if (strByte[leftP] <= '9') && (strByte[leftP] >= '0') {
+			for i, tmpByte := range tmpBytes {
+				strByte[rightP-len(tmpBytes)+i+1] = tmpByte
+			}
+			rightShift = len(tmpBytes)
+		} else {
+			strByte[rightP] = strByte[leftP]
+		}
+		// 更新指针
+		rightP -= rightShift
+		leftP -= 1
+	}
+	return string(strByte)
+}
+
+func main(){
+	var strByte []byte
+	fmt.Scanln(&strByte)
+
+    newString := replaceNumber(strByte)
+
+	fmt.Println(newString)
+}
+````