797. Search a 2D Matrix

You are searching a sorted grid where each row is sorted left to right, and the first value of each row is greater than the last value of the previous row.

Given an m x n matrix and a target, return true if the target exists in the matrix. Otherwise, return false.

Examples

searchMatrix([[1,3,5,7],[10,11,16,20],[23,30,34,60]], 3);  // true
searchMatrix([[1,3,5,7],[10,11,16,20],[23,30,34,60]], 13); // false