JZ-C-33

剑指offer第三十三题：把数组排成最小的数

//============================================================================
// Name        : JZ-C-33.cpp
// Author      : Laughing_Lz
// Version     :
// Copyright   : All Right Reserved
// Description : 把数组排成最小的数
//============================================================================

#include <iostream>
#include <string>
#include "string.h"
#include <algorithm>
#include <stdio.h>
using namespace std;

int compare(const void* strNumber1, const void* strNumber2);

// int型整数用十进制表示最多只有10位
const int g_MaxNumberLength = 10;

char* g_StrCombine1 = new char[g_MaxNumberLength * 2 + 1];
char* g_StrCombine2 = new char[g_MaxNumberLength * 2 + 1];

void PrintMinNumber(int* numbers, int length)
{
    if(numbers == NULL || length <= 0)
        return;

    char** strNumbers = (char**)(new int[length]);
    for(int i = 0; i < length; ++i)
    {
        strNumbers[i] = new char[g_MaxNumberLength + 1];
        sprintf(strNumbers[i], "%d", numbers[i]);
    }

    qsort(strNumbers, length, sizeof(char*), compare);//从小到大排序，排序规则为compare函数★

    for(int i = 0; i < length; ++i)
        printf("%s", strNumbers[i]);
    printf("
");

    for(int i = 0; i < length; ++i)
        delete[] strNumbers[i];
    delete[] strNumbers;
}

// 如果[strNumber1][strNumber2] > [strNumber2][strNumber1], 返回值大于0
// 如果[strNumber1][strNumber2] = [strNumber2][strNumber1], 返回值等于0
// 如果[strNumber1][strNumber2] < [strNumber2][strNumber1], 返回值小于0
int compare(const void* strNumber1, const void* strNumber2)//这里定义排序规则★
{
    // [strNumber1][strNumber2]
    strcpy(g_StrCombine1, *(const char**)strNumber1);
    strcat(g_StrCombine1, *(const char**)strNumber2);

    // [strNumber2][strNumber1]
    strcpy(g_StrCombine2, *(const char**)strNumber2);
    strcat(g_StrCombine2, *(const char**)strNumber1);

    return strcmp(g_StrCombine1, g_StrCombine2);
}

// ====================测试代码====================
void Test(char* testName, int* numbers, int length, char* expectedResult)
{
    if(testName != NULL)
        printf("%s begins:
", testName);

    if(expectedResult != NULL)
        printf("Expected result is: 	%s
", expectedResult);

    printf("Actual result is: 	");
    PrintMinNumber(numbers, length);

    printf("
");
}

void Test1()
{
    int numbers[] = {3, 5, 1, 4, 2};
    Test("Test1", numbers, sizeof(numbers)/sizeof(int), "12345");
}

void Test2()
{
    int numbers[] = {3, 32, 321};
    Test("Test2", numbers, sizeof(numbers)/sizeof(int), "321323");
}

void Test3()
{
    int numbers[] = {3, 323, 32123};
    Test("Test3", numbers, sizeof(numbers)/sizeof(int), "321233233");
}

void Test4()
{
    int numbers[] = {1, 11, 111};
    Test("Test4", numbers, sizeof(numbers)/sizeof(int), "111111");
}

// 数组中只有一个数字
void Test5()
{
    int numbers[] = {321};
    Test("Test5", numbers, sizeof(numbers)/sizeof(int), "321");
}

void Test6()
{
    Test("Test6", NULL, 0, "Don't print anything.");
}


int main(int argc, char** argv)
{
    Test1();
    Test2();
    Test3();
    Test4();
    Test5();
    Test6();

    return 0;
}