LeetCode: Remove Element

简单题， 一次过

class Solution {
public:
    int removeElement(int A[], int n, int elem) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int dup = 0;
        for (int i = 0; i < n; i++) {
            while (A[i] == elem && i+dup < n) {
                dup++;
                for (int j = i; j < n-1; j++) A[j] = A[j+1];
            }
        }
        return n - dup;
    }
};

 再贴一个时间复杂度低但是空间复杂度高的

class Solution {
public:
    int removeElement(int A[], int n, int elem) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<int> B;
        for (int i = 0; i < n; i++) {
            if (A[i] == elem) continue;
            B.push_back(A[i]);
        }
        for (int i = 0; i < B.size(); i++) A[i] = B[i];
        return B.size();
    }
};

 C#

public class Solution {
    public int RemoveElement(int[] nums, int val) {
        List<int> ans = new List<int>();
        for (int i = 0; i < nums.Length; i++) {
            if (nums[i] == val) continue;
            ans.Add(nums[i]);
        }
        for (int i = 0; i < ans.Count; i++) nums[i] = ans[i];
        return ans.Count;
    }
}