Search2DMatrix.java

// #74. Search a 2D Matrix 
// Time Complexity : O(log(m*n))
// Space Complexity : O(1)
// Did this code successfully run on Leetcode : Yes
// Any problem you faced while coding this : No

public class Search2DMatrix {
    public boolean searchMatrix(int[][] matrix, int target) {
        int m = matrix.length;
        int n = matrix[0].length;

        int low = 0;
        int high = (m*n) - 1;
        while(low <= high){
            int mid = low + (high - low)/2;
            int r = mid / n;
            int c = mid % n;

            if(matrix[r][c] == target){
                return true;
            }
            else if (target > matrix[r][c]){
                low = mid+1;
            }else {
                high = mid -1;
            }
        }
        return false;
    }
}