LeetCode27.移除元素

Posted 2020-12-03 lettleshel

class Solution {
public:
    int removeElement(vector<int>& nums, int val) {
        if(nums.empty()) return 0;
        int l=0;
        int r=nums.size()-1;
        while(l<r){
            if(nums[l]==val) {
                while(l<r&&nums[r]==val) {
                    r--;
                    if(l==r) break;
                }
                swap(nums[l],nums[r]);
                r--;
            }
            l++;
        }
        if(nums[r]!=val) r++; 
        return r;
    }
};