关于按下ctrl+z后，之后的cin失效的问题

下面这代码按下Ctrl+z结束while输入后，接下来的cin >> val2就无法输入了

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <typeinfo>

using namespace std;

int main()
{
	vector<int> vi;
	int val;
	while (cin >> val)
		vi.push_back(val);
	int val2;
	cout << "Please enter the integers that you want to seek:" << endl;
	cin >> val2;
	cout << "The sequence contains " << (count(vi.cbegin(), vi.cend(), val2)) << " " << val2 << endl;

	return 0;
}

必须在结束while后加一条cin.clear()才能正常运行（注意：要先按回车，再按ctrl+z，因为ctrl+z位于行首才表示结束输入，否则只会被当成一个字符来处理，Ctrl+z的ASCII码是26）

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <typeinfo>

using namespace std;

int main()
{
	vector<int> vi;
	int val;
	while (cin >> val)
		vi.push_back(val);
	int val2;
	cin.clear();
	cout << "Please enter the integers that you want to seek:" << endl;
	cin >> val2;
	cout << "The sequence contains " << (count(vi.cbegin(), vi.cend(), val2)) << " " << val2 << endl;

	return 0;
}

https://www.cnblogs.com/hubavyn/p/3996413.html节选自此博客