劍指offer42-翻轉單詞順序和字符串的左旋轉

翻轉句子中的單詞順序，輸入一個句子，翻轉句子中的單詞順序，但是單個單詞中的字母順序不變，如“I am a student.”翻轉後爲“student. a am I”。翻轉方式爲，首先將整個句子當成是一個字符串進行翻轉，得到“.tneduts a ma I”。然後，以空格作爲分隔符，將每個單詞分別進行翻轉，得到“student. a am I”，而對於整個句子和單個單詞的翻轉，其翻轉的方式是一樣的

#include <iostream>
using namespace std;
//輸入一個字符串的頭和尾指針，將其中的所有字符進行翻轉
void reversestr(char* strBegin, char* strEnd)
{
    while (strBegin < strEnd)
    {
        char tmpchar;
        tmpchar = *strBegin;
        *strBegin = *strEnd;
        *strEnd = tmpchar;
        strBegin++;
        strEnd--;
    }
}
void ReverseSentence(char* input)
{
    if (input==NULL)
    {
        return;
    }
    char* strBegin = input;
    char* strEnd = input;
    while (*strEnd!='\0')
    {
        strEnd++;
    }
    strEnd--;
    reversestr(strBegin, strEnd);     //整個句子作爲一個字符串進行翻轉
    while (*strBegin!='\0')
    {
        strEnd = strBegin;
        while (*strEnd != ' ' && *strEnd != '\0')
        {
            strEnd++;
        }
        strEnd--;
        reversestr(strBegin, strEnd);          //翻轉單個單詞
        strBegin = ++strEnd;
        while (*strBegin==' ')
        {
            strBegin++;
        }
    }

}
// ====================測試代碼====================
void Test(char* testName, char* input, char* expectedResult)
{
    if (testName != NULL)
        printf("%s begins: ", testName);

    ReverseSentence(input);

    if ((input == NULL && expectedResult == NULL)
        || (input != NULL && strcmp(input, expectedResult) == 0))
        printf("Passed.\n\n");
    else
        printf("Failed.\n\n");
}

// 功能測試，句子中有多個單詞
void Test1()
{
    char input[] = "I am a student.";
    char expected[] = "student. a am I";

    Test("Test1", input, expected);
}

// 功能測試，句子中只有一個單詞
void Test2()
{
    char input[] = "Wonderful";
    char expected[] = "Wonderful";

    Test("Test2", input, expected);
}

// 魯棒性測試
void Test3()
{
    Test("Test3", NULL, NULL);
}

// 邊界值測試，測試空字符串
void Test4()
{
    Test("Test4", "", "");
}

// 邊界值測試，字符串中只有空格
void Test5()
{
    char input[] = "   ";
    char expected[] = "   ";
    Test("Test5", input, expected);
}

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

    return 0;
}

//將字符串中的前面一部分移到字符串的尾部，而將剩下的字符前移
//如“abcdefgh”，旋轉3個字符後爲“defghabc”

#include <iostream>
using namespace std;
char* RotateString(char* input,int n)
{
    if (input == NULL )
    {
        return NULL;
    }
    if (n == 0)
    {
        return input;
    }
    char* FirstPartBegin = input;
    char* FirstPartEnd = input + n - 1;
    char* SecondPartBegin = input + n;
    char* SecondPartEnd = input + n;
    while (*SecondPartEnd != '\0')
    {
        SecondPartEnd++;
    }
    SecondPartEnd--;
    //reversestr函數與前面的一樣
    reversestr(FirstPartBegin, FirstPartEnd);
    reversestr(SecondPartBegin, SecondPartEnd);
    reversestr(FirstPartBegin, SecondPartEnd);
    return FirstPartBegin;
}

// ====================測試代碼====================
void Test(char* testName, char* input, int num, char* expectedResult)
{
    if (testName != NULL)
        printf("%s begins: ", testName);

    char* result = RotateString(input, num);

    if ((input == NULL && expectedResult == NULL)
        || (input != NULL && strcmp(result, expectedResult) == 0))
        printf("Passed.\n\n");
    else
        printf("Failed.\n\n");
}

// 功能測試
void Test1()
{
    char input[] = "abcdefg";
    char expected[] = "cdefgab";

    Test("Test1", input, 2, expected);
}

// 邊界值測試
void Test2()
{
    char input[] = "abcdefg";
    char expected[] = "bcdefga";

    Test("Test2", input, 1, expected);
}

// 邊界值測試
void Test3()
{
    char input[] = "abcdefg";
    char expected[] = "gabcdef";

    Test("Test3", input, 6, expected);
}

// 魯棒性測試
void Test4()
{
    Test("Test4", NULL, 6, NULL);
}

// 魯棒性測試
void Test5()
{
    char input[] = "abcdefg";
    char expected[] = "abcdefg";

    Test("Test5", input, 0, expected);
}

// 魯棒性測試
void Test6()
{
    char input[] = "abcdefg";
    char expected[] = "abcdefg";

    Test("Test6", input, 7, expected);
}

int main(int argc, char* argv[])
{
    Test1();
    Test2();
    Test3();
    Test4();
    Test5();
    Test6();
    return 0;
}