Plus ONe

Change-Id: I3d9f1a742c99bf4415dae6d14dd540041f31280a

Author: applewjg

PlusOne.java

@@ -0,0 +1,28 @@
+/*
+ Author:     King, [email protected]
+ Date:       Dec 25, 2014
+ Problem:    Plus One
+ Difficulty: Easy
+ Source:     https://oj.leetcode.com/problems/plus-one/
+ Notes:
+ Given a number represented as an array of digits, plus one to the number.
+
+ Solution: ...
+ */
+
+public class Solution {
+    public int[] plusOne(int[] digits) {
+        if (digits.length == 0) return digits;
+        int carry = 1;
+        for (int i = digits.length - 1; i >= 0; --i) {
+            digits[i] += carry;
+            carry = digits[i] / 10;
+            digits[i] = digits[i] % 10;
+        }
+        if (carry == 0) return digits;
+        int[] res = new int[digits.length + 1];
+        res[0] = carry;
+        System.arraycopy(digits, 0, res, 1, digits.length);
+        return res;
+    }
+}