C++ string中substr用法

s.substr（star， length）是用来获取字符串s中的一段字串

Examp：s=“0123456789”；s.substr（2， 5）=“23456”；s.substr（0， 5）=“01234”；

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

int main()
{
        string s;
        while (cin >> s) {
                for (int i = 0; i < 5; i ++) {
                        cout << s.substr(i, 5) << endl;
                }
        }
}

输入asdfghjkl

结果为：

asdfg
sdfgh
dfghj
fghjk
ghjkl

输入asdfghj

结果为：

asdfg
sdfgh
dfghj
fghj
ghj

输入：as

结果为：

as

s

terminate called after throwing an instance of 'std::out_of_range'

  what():  basic_string::substr: __pos (which is 3) > this->size() (which is 2)

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.