Submission #1111465

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
1111465	2024-11-12T08:42:40 Z	YSH2020	Fire (BOI24_fire)	C++17	0 / 100	1 ms	336 KB

Main

#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, m; cin >> n >> m;
	vector<pair<int, int>> shifts;
	int max_dist = 0;
	for (int i = 0; i < n; i++) {
		int x, y; cin >> x >> y;
		if (x > y) y += m;
		if (y-x > max_dist) {max_dist = y-x;}
		shifts.push_back({x, y});
	}
	for (int i=0; i < n; i++) {
		shifts[i] = {(shifts[i].first-max_dist+m)%m, (shifts[i].second-max_dist+m)%m};
		if (shifts[i].first > shifts[i].second) shifts[i]={shifts[i].first, shifts[i].second+m};
	}
	sort(shifts.begin(), shifts.end());
	int time = 0;
	int furthest_time = 0;
	int c = 0;
	for (int i=0; i < n; i++) {
		if (shifts[i].first <= time) furthest_time = max(furthest_time, shifts[i].second);
		else {
			c++;
			time = furthest_time;
			if (time >= m) {cout << c; return 0;}
			if (shifts[i].first > time) {cout << -1; return 0;}
			furthest_time = shifts[i].second;
		}
	}
	c++;
	time = furthest_time;
	if (time >= m) {cout << c; return 0;}
	else cout << -1;
}

Subtask #1

0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Incorrect	1 ms	336 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #2

0 / 17.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Incorrect	1 ms	336 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #3

0 / 9.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Incorrect	1 ms	336 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #4

0 / 13.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Incorrect	1 ms	336 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #5

0 / 21.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Correct	1 ms	336 KB	Output is correct
4	Correct	1 ms	336 KB	Output is correct
5	Correct	1 ms	336 KB	Output is correct
6	Correct	1 ms	336 KB	Output is correct
7	Correct	1 ms	336 KB	Output is correct
8	Incorrect	1 ms	336 KB	Output isn't correct
9	Halted	0 ms	0 KB	-

Subtask #6

0 / 26.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	336 KB	Output is correct
2	Correct	1 ms	336 KB	Output is correct
3	Incorrect	1 ms	336 KB	Output isn't correct
4	Halted	0 ms	0 KB	-