Submission #359097

#	Time	Username	Problem	Language	Result	Execution time	Memory
359097		jesus_coconut	Tower Defense (CEOI19_towerdefense)	C++17	53 / 100	2 ms	512 KiB

towerdefense

#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;

pii s, t;
int d;

void read() {
	cin >> s.first >> s.second;
	cin >> t.first >> t.second;
	cin >> d;
}

int dist(pii s, pii t) {
	return abs(s.first - t.first) + abs(s.second - t.second);
}

void solve() {
	read();
	int dd = d - dist(s, t);
	if (dd == 0) {
		cout << 0 << '\n';
	} else if (dd < 0 || dd % 2 || dist(s, t) == 1) {
		cout << "impossible\n";
	} else {
		vector<pair<int, int>> ans;
		if (abs(s.first - t.first) > 1) {
			int x = t.first + (s.first - t.first) / abs(s.first - t.first);
			for (int i = min(s.second, t.second); i <= max(s.second, t.second); ++i) {
				ans.emplace_back(x, i);
			}
			dd -= 2;
			int mn = min(s.second, t.second) - 1;
			int mx = max(s.second, t.second) + 1;
			while (dd > 0) {
				ans.emplace_back(x, mn);
				ans.emplace_back(x, mx);
				dd -= 2;
				--mn;
				++mx;
			}
		} else if (abs(s.second - t.second) > 1){
			int y = t.second + (s.second - t.second) / abs(s.second - t.second);
			for (int i = min(s.first, t.first); i <= max(s.first, t.first); ++i) {
				ans.emplace_back(i, y);
			}
			dd -= 2;
			int mn = min(s.first, t.first) - 1;
			int mx = max(s.first, t.first) + 1;
			while (dd > 0) {
				ans.emplace_back(mn, y);
				ans.emplace_back(mx, y);
				dd -= 2;
				--mn;
				++mx;
			}
		} else {
			ans.emplace_back(min(s.first, t.first), max(s.second, t.second));
			ans.emplace_back(max(s.first, t.first), min(s.second, t.second));
			dd -= 4;
			if (dd < 0 || dd % 2) {
				cout << "impossible\n";
				return;
			} else {
				auto a1 = ans[0], a2 = ans[1];
				int dx1 = 1, dx2 = 1;
				{
					auto tmp = a1;
					tmp.first += dx1;
					if (tmp == s || tmp == t) dx1 = -1;
					tmp = a2;
					tmp.first += dx2;
					if (tmp == s || tmp == t) dx2 = -1;
				}
				while (dd > 0) {
					a1.first += dx1;
					a2.first += dx2;
					ans.emplace_back(a1);
					ans.emplace_back(a2);
					dd -= 2;
				}
			}
		}
		cout << ans.size() << '\n';
		for (auto &[a, b] : ans) cout << a << ' ' << b << '\n';
	}
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);

	solve();

	return 0;
}

• Subtask 1: 25 / 25
• Subtask 2: 28 / 28
• Subtask 3: 0 / 47