C++ Program to Print matrix in snake pattern

Given an n x n matrix in the given matrix, you have to print the elements of the matrix in the snake pattern.

Examples:

Input :mat[][] = { {10, 20, 30, 40},
                   {15, 25, 35, 45},
                   {27, 29, 37, 48},
                   {32, 33, 39, 50}};
              
Output : 10 20 30 40 45 35 25 15 27 29
         37 48 50 39 33 32 

Input :mat[][] = { {1, 2, 3},
                   {4, 5, 6},
                   {7, 8, 9}};
Output : 1 2 3 6 5 4 7 8 9

We traverse all rows. For every row, we check if it is even or odd. If even, we print from left to right else print from right to left. 

C++

// C++ program to print matrix in snake order
#include <iostream>
#define M 4
#define N 4
using namespace std;

void print(int mat[M][N])
{
    // Traverse through all rows
    for (int i = 0; i < M; i++) {

        // If current row is even, print from
        // left to right
        if (i % 2 == 0) {
            for (int j = 0; j < N; j++)
                cout << mat[i][j] << " ";

        // If current row is odd, print from
        // right to left
        } else {
            for (int j = N - 1; j >= 0; j--)
                cout << mat[i][j] << " ";
        }
    }
}

// Driver code
int main()
{
    int mat[][] = { { 10, 20, 30, 40 },
                    { 15, 25, 35, 45 },
                    { 27, 29, 37, 48 },
                    { 32, 33, 39, 50 } };

    print(mat);
    return 0;
}

Output :

10 20 30 40 45 35 25 15 27 29 37 48 50 39 33 32 

Time complexity: O(N^2) for given N*N matrix

Auxiliary Space: O(1)

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