spiral-matrix.cpp

vector<int> spiralOrder(vector<vector<int>>& matrix) {
    int n = matrix.size();
    int m = matrix[0].size();

    int top = 0, bottom = n-1;
    int left = 0, right = m-1;

    vector<int> ans;

    while(top <= bottom && left <= right){

        for(int j = left; j <= right; j++)
            ans.push_back(matrix[top][j]);
        top++;

        for(int i = top; i <= bottom; i++)
            ans.push_back(matrix[i][right]);
        right--;

        if(top <= bottom){
            for(int j = right; j >= left; j--)
                ans.push_back(matrix[bottom][j]);
            bottom--;
        }

        if(left <= right){
            for(int i = bottom; i >= top; i--)
                ans.push_back(matrix[i][left]);
            left++;
        }
    }

    return ans;
}