public class Solution { public static boolean find(int target, int [][] array) { if (array == null) return false; int rows = array.length; if (rows == 0) return false; int cols = array[0].length; if (cols == 0) return false; // 定位到右上 int row = 0; int col = cols - 1; while (row < rows && col >= 0) { if (array[row][col] > target) { col--; } else if (array[row][col] < target) { row++; } else { return true; } } return false; } }