/*******************************************************************Copyright(c) 2018, htfengAll rights reserved.*******************************************************************///==================================================================// 《剑指Offer——名企面试官精讲典型编程题》C++代码//// 面试题5：字符串替换空格// 题目：实现一个函数，把字符串中的每个空格替换成“%20”（空格的ASCII为32,十六进制的0x20）//==================================================================#include
    
     using namespace std;// 功能函数void ReplaceBlank(char string[], int length) {    if (string == nullptr || length < 0)        return;    // 遍历一次得到字符串长度和空格个数    int orignalLength = 0;    int numberOfBlank = 0;    int i = 0;    while (string[i] != '\0') {        ++orignalLength;        if (string[i] == ' ')            ++numberOfBlank;        ++i;    }    // 把空格替换成“%20”后字符串长度为newLength    int newLength = orignalLength + numberOfBlank * 2;    if (newLength > length)        return;    int indexOfOriginal = orignalLength;    int indexOfNew = newLength;    while (indexOfOriginal >= 0 && indexOfNew > indexOfOriginal) {        if (string[indexOfOriginal] == ' ') {            string[indexOfNew--] = '0';            string[indexOfNew--] = '2';            string[indexOfNew--] = '%';        }        else {            string[indexOfNew--] = string[indexOfOriginal];        }        --indexOfOriginal;    }}//================================测试代码==================================void Test(char *testName, char string[], int length, char except[]) {    if (testName != nullptr)        cout << testName << ":";    ReplaceBlank(string, length);    if (except == nullptr && string == nullptr)        cout << "passed." << endl;    else if (except == nullptr && string != nullptr)        cout << "failed." << endl;    else if(strcmp(string, except) == 0)        cout << "passed." << endl;    else        cout << "failed." << endl;}// 输入的字符串中包含空格void test1() {    const int length = 100;    char str[length] = "hello world";    char test[] = "test1";    char except[] = "hello%20world";    Test(test, str, length, except);}// 输入的字符串中没有空格void test2() {    const int length = 100;    char str[length] = "helloworld";    char test[] = "test2";    char except[] = "helloworld";    Test(test, str, length, except);}// 字符串是个nullptr指针void test3() {    const int length = 0;    char test[] = "test3";    Test(test, nullptr, length, nullptr);}// 主函数int main() {    test1();    test2();    test3();    system("pause");    return 0;}