public boolean searchMatrix(int[][] matrix, int target) {
if (matrix == null || matrix.length == 0) {
int m = matrix.length, n = matrix[0].length;
int start = 0, end = m * n - 1, mid = 0;
mid = start + (end - start) / 2;
if (matrix[row][col] == target) {
else if (matrix[row][col] < target) {