search in a matrix whose each row and column is sorted

/*
https://practice.geeksforgeeks.org/problems/search-in-a-matrix17201720/1
Logic:
remove a row or column in each comparison until an element is found.
if top-right element is greater than x then we can't go downwards because
whole column will have a greater elements so only one option left,go left
side and same goes for each position of array.
Time complexity: O(n+m)
*/
class Solution{
public:
    int matSearch (vector <vector <int>> &arr, int n, int m, int x){
        int i=0,j=m-1;
        while(i<n && j>=0){
            if(arr[i][j]>x){
                j--;
            }
            else if(arr[i][j]<x){
                i++;
            }
            else return 1;
        }
        return 0;
    }
};