In reply to Shashank Gurijala:
Diagonal should follow like below from right to left
1 3 1 6
1 4 6 1
1 6 4 3
6 1 1 3
whole output should be
1 2 3 4 6
2 3 4 6 1
2 4 6 3 2
1 6 5 4 3
6 4 3 2 1
Note:
- diagonal matrix left side values should be increment from starting
- diagonal matrix right side should be decrement value from diagonal
Ex: row=3 or i=2
2 and 4 incremented before 6
3 and 2 decremented after 6