[LeetCode]Remove Duplicates from Sorted Array

題目：

Remove Duplicates from Sorted Array

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.

Do not allocate extra space for another array, you must do this in place with constant memory.

For example,
Given input array A = [1,1,2],

Your function should return length = 2, and A is now [1,2].

來源：https://oj.leetcode.com/problems/remove-duplicates-from-sorted-array/

思路：

因爲是有序的數組，只要前後指針，一次遍歷就行。

C++ AC代碼：

class Solution {
public:
    int removeDuplicates(int A[], int n) {
        if( n < 2)
		    return n;
		int i=0, j=1;
		while( i < n && j < n ){
		    if( A[i] == A[j] )
			    j++;
			else
			    A[++i] = A[j++];	
		}
		return i+1;
    }
};

運行時間 116ms