Check if Every Row and Column Contains All Numbers.cpp

// Runtime: 310 ms (Top 66.03%) | Memory: 67.9 MB (Top 58.35%)
class Solution {
public:
    bool checkValid(vector<vector<int>>& matrix) {
        int n=matrix.size();
        unordered_set<int> s1, s2;
        for(int i=0;i<n;i++)
        {
            for(int j=0;j<n;j++)
            {
                if(s1.find(matrix[i][j])!=s1.end())
                    return false;
                else
                    s1.insert(matrix[i][j]);
                if(s2.find(matrix[j][i])!=s2.end())
                    return false;
                else
                    s2.insert(matrix[j][i]);
            }
            s1.clear();
            s2.clear();
        }
        return true;
    }
};