Search In A Row Wise And Column Wise Sorted Matrix

Posted: 30 Oct, 2020
Difficulty: Moderate

PROBLEM STATEMENT

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You are given an N * N matrix of integers where each row and each column is sorted in increasing order. You are given a target integer 'X'. Find the position of 'X' in the matrix, if it exists then return the pair {i, j} where 'i' represents the row and 'j' represents the column of the array, otherwise return {-1,-1}

For example: If the given matrix is:

[ [1, 2, 5],
  [3, 4, 9],
  [6, 7, 10]] 
We have to find the position of 4. We will return {1,1} since A[1][1] = 4.
Input Format:
The first line of input contains a single integer 'T', representing the number of test cases or queries to be run. 
Then the 'T' test cases follow.
The first line of each test case contains two space-separated integers 'N' and 'X', representing the size of the matrix and the target element respectively.
Each of the next 'N' lines contains 'N' space-separated integers representing the elements of the matrix.
Output Format:
For each test case, print the position of 'X', if it exists, otherwise print “-1 -1”.
Constraints:
1 ≤ T ≤ 10
1 ≤ N ≤ 10^3
1 ≤ X ≤ 10^6
1 ≤ Aij ≤ 10^6

where 'T' is the number of test cases, 'N' is the number of rows and columns, 'X' is the target value, and Aij is the elements of the matrix.
Time Limit : 1 sec 

Note:

It is guaranteed that the matrix contains distinct elements.
You are not required to print the expected output, it has already been taken care of. Just implement the function.
Approach 1
  • Run a loop from i = 0 to N - 1, to check each row.
    • Run a loop from j = 0 to N - 1, to check each element of the row.
      • If there is a match, return {i, j}.
  • If the element is not found in the entire matrix, return {-1, -1}
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