Given a square matrix of order n*n, you have to interchange the elements of both diagonals.
Examples :
Input : matrix[][] = {1, 2, 3, 4, 5, 6, 7, 8, 9} Output : matrix[][] = {3, 2, 1, 4, 5, 6, 9, 8, 7} Input : matrix[][] = {4, 2, 3, 1, 5, 7, 6, 8, 9, 11, 10, 12, 16, 14, 15, 13} Output : matrix[][] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 11, 14, 15, 16}
Explanation : Idea behind interchanging diagonals of a square matrix is simple. Iterate from 0 to n-1 and for each iteration you have to swap a[i][i] and a[i][n-i-1].
C++
// C++ program to interchange // the diagonals of matrix #include<bits/stdc++.h> using namespace std;
#define N 3 // Function to interchange diagonals void interchangeDiagonals( int array[][N])
{ // swap elements of diagonal
for ( int i = 0; i < N; ++i)
if (i != N / 2)
swap(array[i][i], array[i][N - i - 1]);
for ( int i = 0; i < N; ++i)
{
for ( int j = 0; j < N; ++j)
cout<< " " << array[i][j];
cout<<endl;
}
} // Driver Code int main()
{ int array[N][N] = {4, 5, 6,
1, 2, 3,
7, 8, 9};
interchangeDiagonals(array);
return 0;
} // This code is contributed by noob2000. |
Output:
6 5 4 1 2 3 9 8 7
Time Complexity: O(N*N), as we are using nested loops for traversing the matrix.
Auxiliary Space: O(1), as we are not using any extra space.
Please refer complete article on Program to Interchange Diagonals of Matrix for more details!
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