comefrom: <awangdev>Search a 2D Matrix_1.java
code: public boolean searchMatrix(int[][] matrix, int target) {
          if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
              return false;
          }
          int row = matrix.length;
          int col = matrix[0].length;
          int start = 0;
          int end = row * col - 1;
          int mid;
  
          while (start + 1 < end) {
              mid = start + (end - start)/2;
              int num = matrix[mid/col][mid%col];
              if (target == num) {
                  return true;
              } else if (num < target) {
                  start = mid;
              } else {
                  end = mid;
              }
          }
  
          return (matrix[start/col][start%col] == target || matrix[end/col][end%col] == target);
      }
masked: public boolean var_0 ( int [ ] [ ] var_1 , int var_2 ) {
    if ( var_1 == null || var_1 . length == 0 || var_1 [ 0 ] . length == 0 ) {
      return false ;
    }
    int var_6 = var_1 . length ;
    int var_7 = var_1 [ 0 ] . length ;
    int var_8 = 0 ;
    int var_10 = var_6 * var_7 - 1 ;
    int var_11 ;
    while ( var_8 + 1 < var_10 ) {
      var_11 = var_8 + ( var_10 - var_8 ) / 2 ;
      int var_13 = var_1 [ var_11 / var_7 ] [ var_11 % var_7 ] ;
      if ( var_2 == var_13 ) {
        return true ;
      }
      else if ( var_13 < var_2 ) {
        var_8 = var_11 ;
      }
      else {
        var_10 = var_11 ;
      }
    }
    return ( var_1 [ var_8 / var_7 ] [ var_8 % var_7 ] == var_2 || var_1 [ var_10 / var_7 ] [ var_10 % var_7 ] == var_2 ) ;
  }
  