#275 · #74 · Search a 2D Matrix(搜索二维矩阵)

You are given an m x n integer matrix with two properties: each row is sorted left to right, and the first integer of each row is greater than the last integer of the previous row. Given a target, return whether it is in the matrix. Constraints: 1 <= m, n <= 100, -10^4 <= matrix[i][j], target <= 10^4.