【C++】【LeetCode】27. Remove Element

题目

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 in place with constant memory.

The order of elements can be changed. It doesn’t matter what you leave beyond the new length.

Example:

Given input array nums = [3,2,2,3], val = 3

Your function should return length = 2, with the first two elements of nums being 2.

思路

遍历数组，如果碰到同val相等的数，则移除，并且将下标前移一位。

代码

class Solution {
public:
int removeElement(vector<int>& nums, int val) {
int n = nums.size();
for (int i=0; i<n; i++) {
if (nums[i] == val) {
nums.erase(nums.begin()+i);
n--;
i--;
}
}
return n;
}
};