#54 Spiral Matrix

Given an m x n matrix, return all elements of the matrix in spiral order.

Example 1:

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [1,2,3,6,9,8,7,4,5]

Example 2:

Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
Output: [1,2,3,4,8,12,11,10,9,5,6,7]

Constraints:

• m == matrix.length
• n == matrix[i].length
• 1 <= m, n <= 10
• -100 <= matrix[i][j] <= 100

Solution :

Given an m x n matrix, return all elements of the matrix in spiral order.

 

Example 1:


Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
Output: [1,2,3,6,9,8,7,4,5]
Example 2:


Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
Output: [1,2,3,4,8,12,11,10,9,5,6,7]
 

Constraints:

m == matrix.length
n == matrix[i].length
1 <= m, n <= 10
-100 <= matrix[i][j] <= 100

Complete code:

// Cyclically rotate an array by one
#include <bits/stdc++.h>
using namespace std;

/*
IN GCC(C language)
*/
int* spirallyTraverse(int r, int c, int m[][5])
{   
	int *result = new int[r*c];
	static int count = 0;
	int i, j=0, k=0;
	int r1 = r-1;
	int c1 = c-1;
	while(count < (r*c))
	{
	if(count < (r*c))
	{
		for(i=k; i<=c1; i++)
		{
			//cout << m[j][i] << " ";
			result[count++] = m[j][i];
		}
		j++;
	}
	
	if(count < (r*c))
	{
		for(i=j;i<=r1; i++)
		{
			//cout << m[i][c1] << " ";
			result[count++] = m[i][c1];
		}
		c1--;
	}
	
	if(count < (r*c))
	{
		for(i=c1; i>=k; i--)
		{
			//cout << m[r1][i] << " ";
			result[count++] = m[r1][i];
		}
		r1--;
	}
	
	if(count < (r*c))
	{
		for(i=r1; i>=j; i--)
		{
			//cout << m[i][k] << " ";
			result[count++] = m[i][k];
		}
		k++;
	}
	}

	return result;

}
/*
For G++ compiler : in C++
*/
vector<int> spiralOrder(vector<vector<int>>& matrix) {
        int m = matrix[0].size();
        int n = matrix.size();
        vector<int> result;
        int sr = 0 , er = n-1 , sc = 0 , ec = m-1;
        while(sr<=er && sc<=ec)
        {
            if(sr<=er && sc<=ec)
            {
                for(int col=sc ; col<=ec ; col++)
                    result.push_back(matrix[sr][col]);
                sr++;
            }
            
            if(sr<=er && sc<=ec)
            {
                for(int row=sr ; row<=er ; row++)
                    result.push_back(matrix[row][ec]);
                ec--;
            }
            
            if(sr<=er && sc<=ec)
            {
                for(int col = ec ; col>=sc ; col--)
                    result.push_back(matrix[er][col]);
                er--;
            }
            
             if(sr<=er && sc<=ec)
            {
                for(int row = er; row>=sr; row--)
                    result.push_back(matrix[row][sc]);
                sc++;
            }
        }
        return result;
    }
	
/*
Another approach
*/
vector<int> spirallyTraverseInCPP(vector<vector<int>>& matrix)
{   
		vector<int> result;
        static int count = 0;
        int i, j=0, k=0;
        int totalElement = matrix.size() * matrix[0].size();
        int r1 = matrix.size()-1;
        int c1 = matrix[0].size()-1;
        while(count < (totalElement))
        {
        if(count < (totalElement))
        {
            for(i=k; i<=c1; i++)
            {
                result.push_back(matrix[j][i]);
                count++;
            }
            j++;
        }

        if(count < (totalElement))
        {
            for(i=j;i<=r1; i++)
            {
                result.push_back(matrix[i][c1]);
                count++;
            }
            c1--;
        }

        if(count < (totalElement))
        {
            for(i=c1; i>=k; i--)
            {
                result.push_back(matrix[r1][i]);
                count++;
            }
            r1--;
        }

        if(count < (totalElement))
        {
            for(i=r1; i>=j; i--)
            {
                result.push_back(matrix[i][k]);
                count++;
            }
            k++;
        }
        }

        return result;

}

int main()
{

        // It is for GCC function(spirallyTraverse)
	/*int matrix[][5] = {{6,6,2,28,2},
			{12,26,3,28,7},
			{22,25,3,4,23}};
	int r = 3, c = 5;
	int *res = spirallyTraverse(r, c, matrix);
	for(int i = 0; i<(r*c); i++)
		cout << res[i] << " ";
	cout << endl;
	delete[] res;*/

	vector<vector<int>> vect = {{1,2,3,4},
						{5,6,7,8},
						{9,10,11,12}};
	int totalElement = vect.size() * vect[0].size();
	//vector<int> res = spirallyTraverseInCPP(vect);
	vector<int> res = spiralOrder(vect);
	for(int i = 0; i<totalElement; i++)
		cout << res[i] << " ";
	return 0;
}