54. Spiral Matrix

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        int rows= matrix.size();
        int cols= matrix[0].size();
        
        vector<int> ans;
        int count=0;
        int length= rows*cols;
        
        int startrow= 0;
        int startcol=0;
        int endrow= rows-1;
        int endcol= cols-1;
        
        while(count <length){
            for(int i=startcol; count <length && i<=endcol; i++){
                ans.push_back(matrix[startrow][i]);
                count++;
            }
            startrow++;
            
            for(int i=startrow; count <length && i<=endrow; i++){
                ans.push_back(matrix[i][endcol]);
                count++;
            }
            endcol--;
            
            for(int i=endcol; count <length && i>= startcol;i--){
                ans.push_back(matrix[endrow][i]);
                count++;
            }
            endrow--;
            
            for(int i=endrow; count <length && i>= startrow;i--){
                ans.push_back(matrix[i][startcol]);
                count++;
            }
            startcol++;
        }
        return ans;
    }
};