Boundary traversal of matrix.cpp

class Solution
{   
    public:
    //Function to return list of integers that form the boundary 
    //traversal of the matrix in a clockwise manner.
    vector<int> boundaryTraversal(vector<vector<int> > matrix, int n, int m) 
    {
        vector<int> ans;
        int i;
        for(i=0;i<m;i++) ans.push_back(matrix[0][i]);
        if(n==1) return ans;
        for(i=1;i<n;i++) ans.push_back(matrix[i][m-1]);
        for(i=m-2;i>=0;i--) ans.push_back(matrix[n-1][i]);
        if(m==1) return ans;
        for(i=n-2;i>0;i--) ans.push_back(matrix[i][0]);
        return ans;
    }
};