程序崩溃并显示"std：：out_of_range"错误

我正在为学校做一个命运之轮项目，遇到了一些指针问题。

这是我在程序中遇到的问题，(cmd输出(：

terminate called after throwing an instance of 'std::out_of_range'
what():  basic_string::compare: __pos (which is 1) > this->size() (which is 0)
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

该游戏的设计与命运之轮游戏类似。我首先要做的是过滤掉"rlstne"字母。这在不使用指针的情况下有效，但我必须使用指针。这是我的完整程序：

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <cctype>
#include <time.h>
#include <Windows.h>
int main(){
std::string original_string = "THIS LINE IS THE GAME";
std::string str1;
std::string str2 = "RLSTNE";
int y = 0;
bool restart = true;
std::string* arr_temp =  new std::string[100];
std::string* arr_temp1 = new std::string[100];
*arr_temp1 = str1;
*arr_temp = str2;
do{
std::cout << "What string?" << std::endl;
getline(std::cin, str1);
std::cout << str1.length() << std::endl;
for(int x = 0; x < str1.length(); x++){
if((arr_temp->compare(0,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}
if((arr_temp->compare(1,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}
if((arr_temp->compare(2,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}
if((arr_temp->compare(3,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}   
if((arr_temp->compare(4,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}
if((arr_temp->compare(5,1, *arr_temp1, x, 1)) == 0){
str1[x] = '_';
}
}
*arr_temp1 = str1;
std::cout << *arr_temp1 <<std::endl;
Sleep(1000);
}while(restart);
}

我想这就是我的程序出错的地方：

std::string str1;
std::string str2 = "RLSTNE";

str1没有初始化为任何值，所以编译器将其视为0长度，但我尝试将其初始化为不同的值。例如original_string的字符串值。

这是代码：

std::string str1 = "THIS LINE IS THE GAME";
std::string str2 = "RLSTNE";

这是输出：

What string?
THIS LINE IS THE GAME
21
_HI_ _I__ I_ _H_ GAM_

但当我试图添加比原始值21更多的值时，我会遇到这个问题：

What string?
THIS LINE IS THE GAMEEEE
24
terminate called after throwing an instance of 'std::out_of_range'
what():  basic_string::compare: __pos (which is 22) > this->size() (which is 21)

所以我的问题是：编译器打印出来的是什么？什么值是22，什么值是21？这个->尺寸是什么意思？__pos是什么意思？

提前谢谢。