面试题3：二维数组查找

bool Find(const int *matrix, int rows, int columns, int number)
{
    int key;
    int indexRow;
    int indexCol;

    /*合法性检查*/
    if((NULL == matrix)||(rows <= 0)||(columns <=0))
    {
        return false;
    }

    /*提升性能，直接和最大最小值比较*/
    if((number < matrix[0])||(number > matrix[rows*columns-1]))
    {
        return false;
    }

    indexRow = 0;
    indexCol = columns - 1;

    /*核心代码*/
    while((indexRow < rows)&&(indexCol >= 0))
    {
        key = matrix[indexRow*columns + indexCol];
        if(key > number)
        {
            indexCol--;
        }
        else if(key < number)
        {
            indexRow++;
        }
        else
        {
            return true;
        }
    }

    return false;
}