#include <iostream>
#include <unordered_map>
#include <utility>
#include <sstream>
using namespace std;

unordered_map<int, bool> mp;

int main()
{
	stringstream ans;
	int n, cnt = 0, now_cnt = 1;
	cin >> n;
	for (register int i = 1; i <= n; i++)
	{
		int x;
		cin >> x;
		if (x == 1)
		{
			mp[i] = true;
		}
	}
	cout << mp.size() << endl;
	unordered_map<int, bool>::iterator it_end = mp.end(), real_it = mp.begin();
	++real_it;
	for (register unordered_map<int, bool>::iterator it = real_it; it != it_end; ++it)
	{
		unordered_map<int, bool>::iterator it_tmp = it;
		--it_tmp;
		cout << it -> first - it_tmp -> first << " ";
	}
	--it_end;
	cout << n - (it_end -> first) + 1 << endl;
	//system("pause");
	return 0;
}

c++14

CF上CE怎么回事，vs没有报错啊！

好像是说什么自减运算符与迭代器不支持，但是……