[程序员面试宝典]空格替换

class Replacement {
public:
    string replaceSpace(string iniString, int length) {
        vector<char> result;
        for(int i=0; i<length; i++)
            {
            if(iniString[i]==' ')
                {
                result.push_back('%');
                result.push_back('2');
                result.push_back('0');
            }
            else
                result.push_back(iniString[i]);
        }
        string str(result.begin(),result.end());
        return str;
    }
};

vector<char> 转string

vector<char> tmp;
string str(tmp.begin(), tmp.end());

char* 转 string

char* chstr;
string str = chstr

string 转char*

string str = "Hi Cpp";
const char* mystr = str.c_str();//const is needed