X

DAYS

:

HOUR

:

MINS

:

SEC

Copied to Clipboard
Number of Palindromic paths in a Matrix
Medium Accuracy: 62.34% Submissions: 2981 Points: 4

Given a matrix containing lower alphabetical characters only of size n*m. We need to count the number of palindromic paths in the given matrix.
A path is defined as a sequence of cells starting from top-left cell and ending at bottom-right cell. We are allowed to move to right and down only from current cell.

 

Example 1:

Input: matrix = {{a,a,a,b},{b,a,a,a},{a,b,b,a}}
Output: 3
Explanation: Number of palindromic paths are 3 
from top-left to bottom-right.
aaaaaa (0, 0) -> (0, 1) -> (1, 1) -> (1, 2) -> 
(1, 3) -> (2, 3)    
aaaaaa (0, 0) -> (0, 1) -> (0, 2) -> (1, 2) -> 
(1, 3) -> (2, 3)    
abaaba (0, 0) -> (1, 0) -> (1, 1) -> (1, 2) -> 
(2, 2) -> (2, 3)

Example 2:

Input: matrix = {{a,b},{c,d}}
Output: 0
Explanation: There is no palindromic paths.

 

Your Task:
You don't need to read or print anyhting. Your task is to complete the function countPalindromicPaths() which takes the matrix as input parameter and returns the total nuumber of palindromic paths modulo 109 + 7.

 

Expected Time Complexity: O(n2*m2)
Space Complexity: O(n*m)

 

Constraints:
1 ≤ n, m ≤ 100

to report an issue on this page.

Editorial

We strongly recommend solving this problem on your own before viewing its editorial. Do you still want to view the editorial?

Yes

All Submissions

My Submissions:

Login to access your submissions.

Number of Palindromic paths in a Matrix

Output Window