solve problem Plus One

Author: P-ppc

README.md

@@ -129,6 +129,7 @@ All solutions will be accepted!
 |747|[Largest Number At Least Twice Of Others](https://leetcode-cn.com/problems/largest-number-at-least-twice-of-others/description/)|[java/py/js](./algorithms/LargestNumberAtLeastTwiceOfOthers)|Easy|
 |455|[assign cookies](https://leetcode-cn.com/problems/assign-cookies/description/)|[java/py/js](./algorithms/AssignCookies)|Easy|
 |415|[Add Strings](https://leetcode-cn.com/problems/add-strings/description/)|[java/py/js](./algorithms/AddStrings)|Easy|
+|66|[Plus One](https://leetcode-cn.com/problems/plus-one/description/)|[java/py/js](./algorithms/PlusOne)|Easy|
 |67|[Add Binary](https://leetcode-cn.com/problems/add-binary/description/)|[java/py/js](./algorithms/AddBinary)|Easy|
 |504|[Base 7](https://leetcode-cn.com/problems/base-7/description/)|[java/py/js](./algorithms/Base7)|Easy|
 |830|[Positions Of Large Groups](https://leetcode-cn.com/problems/positions-of-large-groups/description/)|[java/py/js](./algorithms/PositionsOfLargeGroups)|Easy|

algorithms/PlusOne/README.md

@@ -0,0 +1,2 @@
+# Plus One
+This problem is easy to solve, like Add Strings

algorithms/PlusOne/Solution.java

@@ -0,0 +1,22 @@
+class Solution {
+    public int[] plusOne(int[] digits) {
+        List<Integer> res = new ArrayList<Integer>();
+        int carry = 1;
+        
+        for (int i = digits.length - 1; i >= 0; i--) {
+            int sum = digits[i] + carry;
+            res.add(0, sum % 10);
+            carry = sum / 10;
+        }
+        
+        if (carry == 1) {
+            res.add(0, 1);
+        }
+        
+        int[] resArray = new int[res.size()];
+        for (int i = res.size() - 1; i >= 0; i--) {
+            resArray[i] = res.get(i);
+        }
+        return resArray;
+    }
+}

algorithms/PlusOne/solution.js

@@ -0,0 +1,18 @@
+/**
+ * @param {number[]} digits
+ * @return {number[]}
+ */
+var plusOne = function(digits) {
+    let res = [],
+        carry = 1
+    
+    digits.reverse().forEach(d => {
+        let sum = d + carry
+        res.unshift(sum % 10)
+        carry = parseInt(sum / 10)
+    })
+    
+    if (carry === 1) res.unshift(1)
+    
+    return res
+};

algorithms/PlusOne/solution.py

@@ -0,0 +1,15 @@
+class Solution(object):
+    def plusOne(self, digits):
+        """
+        :type digits: List[int]
+        :rtype: List[int]
+        """
+        res = []
+        carry = 1
+        
+        for i in range(len(digits))[::-1]:
+            sm = digits[i] + carry
+            res.insert(0, sm % 10)
+            carry = sm / 10
+            
+        return res if carry == 0 else [1] + res