#include <iostream>
#include <string>
using namespace std;
int main()
{
//char ch1[10] = "gh";
//char ch2[] = "abcdef";
//strncpy(ch1,ch2,6);
//cout<<ch1<<endl;
string str1="hello word";
//string str2="xianglingchuan";
//支持char字符串
//char str2[] = "xianglingchuan";
//支持char型字符
char str2='a';
str1.replace(0,2,2,str2);
cout<<str1<<endl;
return 0;
}