solution.cpp

struct Node
{
    int x,y;
    Node(int _x,int _y):x(_x),y(_y){}
};

class Solution 
{
public:
    vector<int> spiralOrder(vector<vector<int> > &matrix) 
    {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<int> result;
        int m=matrix.size();
        if(m==0)
            return result;
        int n=matrix[0].size();
        if(n==0)
            return result;

        Node a(0,0);
        Node b(m-1,n-1);
        int e = m < n ? m : n;
        e = e/2;
        while(e--)
        {
            for(int i=a.y;i<=b.y;i++)
                result.push_back(matrix[a.x][i]);
            for(int i=a.x+1;i<=b.x;i++)
                result.push_back(matrix[i][b.y]);
            for(int i=b.y-1;i>=a.y;i--)
                result.push_back(matrix[b.x][i]);
            for(int i=b.x-1;i>a.x;--i)
                result.push_back(matrix[i][a.y]);
            a.x++;
            a.y++;
            b.x--;
            b.y--;
        }
            
        if(a.x==b.x)
        {
            for(int i=a.y;i<=b.y;i++)
                result.push_back(matrix[a.x][i]);
        }
        else if(a.y==b.y)
        {
            for(int i=a.x;i<=b.x;i++)
                result.push_back(matrix[i][a.y]);
        }
        return result;
    }
};