Submission #213237

#	Time	Username	Problem	Language	Result	Execution time	Memory
213237		pavement	Tower Defense (CEOI19_towerdefense)	C++17	100 / 100	7 ms	768 KiB

towerdefense

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define mp make_pair
#define mt make_tuple

int xe, ye, xh, yh, c, d, dr[] = {-1, 0, 0, 1}, dc[] = {0, -1, 1, 0};
vector<pair<int, int> > mv;
set<pair<int, int> > s;

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> xe >> ye >> xh >> yh >> d;
	c = llabs(xe - xh) + llabs(ye - yh);
	if ((c > d || (c & 1) ^ (d & 1)) || (c == 1 && c ^ d)) return cout << "impossible\n", 0;
	if (yh > ye) {
		swap(xe, xh);
		swap(ye, yh);
	}
	if (llabs(xe - xh) == 1 && llabs(ye - yh) == 1) {
		if (d == 4) return cout << "impossible\n", 0;
		if (d == 2) {
			mv.emplace_back(xh, ye);
			mv.emplace_back(xe, ye);
			mv.emplace_back(xh, yh);
		} else {
			d -= 6;
			int up = d >> 1, down = 2 + (d >> 1);
			for (int i = 0; i <= up; i++) mv.emplace_back(xe, ye + i);
			if (xe >= xh) {
				mv.emplace_back(xe, ye + up + 1);
				mv.emplace_back(xe - 1, ye + up + 1);
				mv.emplace_back(xe - 2, ye + up + 1);
				for (int i = 0; i <= down; i++) mv.emplace_back(xh - 1, yh + i);
			} else {
				mv.emplace_back(xe, ye + up + 1);
				mv.emplace_back(xe + 1, ye + up + 1);
				mv.emplace_back(xe + 2, ye + up + 1);
				for (int i = 0; i <= down; i++) mv.emplace_back(xh + 1, yh + i);
			}
			mv.emplace_back(xh, yh);
		}
	} else if (xe == xh) {
		for (int i = xe; i < xe + (d - c >> 1); i++) mv.emplace_back(i, ye);
		for (int i = ye; i >= yh; i--) mv.emplace_back(xe + (d - c >> 1), i);
		for (int i = xe; i < xe + (d - c >> 1); i++) mv.emplace_back(i, yh);
	} else if (ye == yh) {
		if (xh > xe) swap(xe, xh);
		for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
		for (int i = xe; i >= xh; i--) mv.emplace_back(i, ye + (d - c >> 1));
		for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xh, i);
	} else if (abs(xe - xh) > 1) {
		if (xe >= xh) {
			for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
			for (int i = xe; i >= xh; i--) mv.emplace_back(i, ye + (d - c >> 1));
			for (int i = ye + (d - c >> 1) - 1; i >= yh; i--) mv.emplace_back(xh, i);
		} else {
			for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
			for (int i = xe; i <= xh; i++) mv.emplace_back(i, ye + (d - c >> 1));
			for (int i = ye + (d - c >> 1) - 1; i >= yh; i--) mv.emplace_back(xh, i);
		}
	} else {
		if (xe >= xh) {
			for (int i = 0; i < (d - c >> 1); i++) mv.emplace_back(xh - i, yh);
			for (int i = yh; i < ye; i++) mv.emplace_back(xh - (d - c >> 1), i);
			for (int i = xh - (d - c >> 1); i <= xe; i++) mv.emplace_back(i, ye);
		} else {
			for (int i = 0; i < (d - c >> 1); i++) mv.emplace_back(xh + i, yh);
			for (int i = yh; i < ye; i++) mv.emplace_back(xh + (d - c >> 1), i);
			for (int i = xh + (d - c >> 1); i >= xe; i--) mv.emplace_back(i, ye);
		}
	}
	sort(mv.begin(), mv.end());
	for (auto i : mv)
		for (int k = 0; k < 4; k++)
			if (!binary_search(mv.begin(), mv.end(), mp(i.first + dr[k], i.second + dc[k]))) s.emplace(i.first + dr[k], i.second + dc[k]);
	cout << s.size() << '\n';
	for (auto i : s) cout << i.first << ' ' << i.second << '\n';
}

Compilation message (stderr)

towerdefense.cpp:11:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
towerdefense.cpp: In function 'int main()':
towerdefense.cpp:45:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = xe; i < xe + (d - c >> 1); i++) mv.emplace_back(i, ye);
                              ~~^~~
towerdefense.cpp:46:58: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = ye; i >= yh; i--) mv.emplace_back(xe + (d - c >> 1), i);
                                                        ~~^~~
towerdefense.cpp:47:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = xe; i < xe + (d - c >> 1); i++) mv.emplace_back(i, yh);
                              ~~^~~
towerdefense.cpp:50:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
                              ~~^~~
towerdefense.cpp:51:61: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = xe; i >= xh; i--) mv.emplace_back(i, ye + (d - c >> 1));
                                                           ~~^~~
towerdefense.cpp:52:32: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xh, i);
                              ~~^~~
towerdefense.cpp:55:33: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
                               ~~^~~
towerdefense.cpp:56:62: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = xe; i >= xh; i--) mv.emplace_back(i, ye + (d - c >> 1));
                                                            ~~^~~
towerdefense.cpp:57:25: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = ye + (d - c >> 1) - 1; i >= yh; i--) mv.emplace_back(xh, i);
                       ~~^~~
towerdefense.cpp:59:33: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = ye; i < ye + (d - c >> 1); i++) mv.emplace_back(xe, i);
                               ~~^~~
towerdefense.cpp:60:62: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = xe; i <= xh; i++) mv.emplace_back(i, ye + (d - c >> 1));
                                                            ~~^~~
towerdefense.cpp:61:25: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = ye + (d - c >> 1) - 1; i >= yh; i--) mv.emplace_back(xh, i);
                       ~~^~~
towerdefense.cpp:65:27: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = 0; i < (d - c >> 1); i++) mv.emplace_back(xh - i, yh);
                         ~~^~~
towerdefense.cpp:66:58: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = yh; i < ye; i++) mv.emplace_back(xh - (d - c >> 1), i);
                                                        ~~^~~
towerdefense.cpp:67:25: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = xh - (d - c >> 1); i <= xe; i++) mv.emplace_back(i, ye);
                       ~~^~~
towerdefense.cpp:69:27: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = 0; i < (d - c >> 1); i++) mv.emplace_back(xh + i, yh);
                         ~~^~~
towerdefense.cpp:70:58: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = yh; i < ye; i++) mv.emplace_back(xh + (d - c >> 1), i);
                                                        ~~^~~
towerdefense.cpp:71:25: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
    for (int i = xh + (d - c >> 1); i >= xe; i--) mv.emplace_back(i, ye);
                       ~~^~~

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