Spiral Matrix

 https://leetcode.com/problems/spiral-matrix/

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        int top=0;
        int left=0;
        int n=matrix.size();
        int m=matrix[0].size();
        int bottom=n-1;
        int right=m-1;
        int direction=0;
        vector<int> ans;
        
        while(left<=right && top<=bottom){
            if(direction==0){
                for(int i=left;i<=right;i++){
                    ans.push_back(matrix[top][i]);
                }
                top++;
            }
            else if(direction==1){
                for(int i=top;i<=bottom;i++){
                    ans.push_back(matrix[i][right]);
                }
                right--;
            }
            else if(direction==2){
                for(int i=right;i>=left;i--){
                    ans.push_back(matrix[bottom][i]);
                }
                bottom--;
            }
            else if(direction==3){
                for(int i=bottom;i>=top;i--){
                    ans.push_back(matrix[i][left]);
                }
                left++;
            }
            direction=(direction+1)%4;
        }
        return ans;
    }
};