Coordinates of the last cell in a Matrix on which performing given operations exits from the Matrix.cpp

class Solution{
    public:
    pair<int,int> endPoints(vector<vector<int>> matrix){
        vector<pair<int, int>> dir = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
        int n = matrix.size(), m = matrix[0].size();
        int i=0, j=0, k=0;
        pair<int, int> ans;
        while(i>=0 && j>=0 && i< n && j<m){
            ans = {i, j};
            if(matrix[i][j]==1){
                matrix[i][j]=0;
                k = (k+1)%4; 
            }
            i = i+dir[k].first;
            j = j+dir[k].second;
        }
        return ans;
    }
};