Leetcode 27. Remove Element(too easy)
Given an array and a value, remove all instances of that value in-place and return the new length.
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
The order of elements can be changed. It doesn't matter what you leave beyond the new length.
Example:
Given nums = [3,2,2,3], val = 3, Your function should return length = 2, with the first two elements of nums being 2.
class Solution { public: int removeElement(vector<int>& nums, int val) { if (nums.size() == 0){ return 0; } int newindex = 0; for (int i = 0; i < nums.size(); i++){ if (nums[i] != val){ nums[newindex] = nums[i]; newindex++; } } return newindex; } };
思路很简单,o(n)的时间复杂度,没有开辟另外的空间,感觉之前做过一个类似的问题。