面试题3：二维数组查找

 1 bool Find(const int *matrix, int rows, int columns, int number)
 2 {
 3     int key;
 4     int indexRow;
 5     int indexCol;
 6 
 7     /*合法性检查*/
 8     if((NULL == matrix)||(rows <= 0)||(columns <=0))
 9     {
10         return false;
11     }
12 
13     /*提升性能，直接和最大最小值比较*/
14     if((number < matrix[0])||(number > matrix[rows*columns-1]))
15     {
16         return false;
17     }
18 
19     indexRow = 0;
20     indexCol = columns - 1;
21 
22     /*核心代码*/
23     while((indexRow < rows)&&(indexCol >= 0))
24     {
25         key = matrix[indexRow*columns + indexCol];
26         if(key > number)
27         {
28             indexCol--;
29         }
30         else if(key < number)
31         {
32             indexRow++;
33         }
34         else
35         {
36             return true;
37         }
38     }
39 
40     return false;
41 }