1. public boolean findNumberIn2DArray(int[][] matrix, int target) {
    2.     //官方
    3.         for (int i = 0; i < matrix.length; i++) {
    4.             int left = 0;
    5.             int right = matrix[0].length-1;
    6.             while (left<=right) {
    7.                 int middle = (left + right) / 2;
    8.                 if (target == matrix[i][middle]) {
    9.                     return true;
    10.                 }
    11.                 if (target > matrix[i][middle]) {
    12.                     left = middle + 1;
    13.                 } else {
    14.                     right = middle - 1;
    15.                 }
    16.             }
    17.         }
    18.         return false;
    19.     }
    23. //大佬
    24.         int i = matrix.length - 1, j = 0;
    25.         while(i >= 0 && j < matrix[0].length)
    26.         {
    27.             if(matrix[i][j] > target) 
    28.                 i--;
    29.             else if(matrix[i][j] < target) 
    30.                 j++;
    31.             else return true;
    32.         }
    33.         return false;