26. Remove Duplicates from Sorted Array

题目

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 nums = [1,1,2],

Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively. It doesn't matter what you leave beyond the new length.

分析

因为去重的是一个已经排好序的数组，所以有重复的数据一定在一起，遍历数组，判断当前数据是否有重复，有重复将重复的数据用后面的数据覆盖

代码

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if (nums.empty())
            return 0;
        int index=0;
        for(int i=1;i<nums.size();i++){
            if (nums[index]!=nums[i]){
                nums[++index]=nums[i]; 
            } 
        } 
        return index+1;
    }
};