《剑指offer》第四题（二维数组中的查找）

// 二维数组中的查找
// 题目：在一个二维数组中，每一行都按照从左到右递增的顺序排序，每一列都按
// 照从上到下递增的顺序排序。请完成一个函数，输入这样的一个二维数组和一个
// 整数，判断数组中是否含有该整数。

#include <iostream>
using namespace std;

bool serach_in(int* matrix, int rows, int cols, int number)
{
    bool flag = false;

    if ((matrix != NULL) && (rows > 0) && (cols > 0))//判断不能忘
    {
        int row = 0, col = cols - 1;
        while ((row < rows) && (col >= 0))
        {
            if (matrix[row*cols + col] == number)
            {
                flag = true;
                break;
            }
            else if (matrix[row*cols + col] > number)//用实例分析过程，思想比程序更重要
                col--;
            else
                row++;
        }
    }

    return flag;
}

void test1()//要查找的数在数组中
{
    cout << "Test1:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 7);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test2()//要查找的数不在数组中
{
    cout << "Test2:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 14);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test3()//要查找的数是数组中最小的数字
{
    cout << "Test3:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 1);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test4()//要查找的数是数组中最大的数字
{
    cout << "Test4:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 15);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test5()//要查找的数比数组中最小的数字还小
{
    cout << "Test5:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 0);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test6()//要查找的数比数组中最大的数字还大
{
    cout << "Test6:\n";
    int matrix[][4] = { {1, 2, 8, 9}, {2, 4, 9, 12}, {4, 7, 10, 13}, {6, 8, 11, 15} };
    bool result;
    result = serach_in(matrix[0], 4, 4, 16);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

void test7()//鲁棒性测试，输入空指针
{
    cout << "Test6:\n";
    bool result;
    result = serach_in(NULL, 0, 0, 1);
    if (result)
        cout << "Yes!\n";
    else
        cout << "No!\n";
}

int main()
{
    test1();
    test2();
    test3();
    test4();
    test5();
    test6();
    test7();//重点，鲁棒性测试

    system("pause");
}