Alien Sunset

#include <bits/stdc++.h>

using namespace std;
bool vittu[22][1000];
int main(){
	int64_t n; cin >> n;
	int64_t h[22], r[22], t[22];
	int64_t d = 0;

	for(int i = 0; i < n; ++i){
		cin >> h[i] >> r[i] >> t[i];
		d = max(d, h[i]);
		int st = r[i]+1;
		while(st != t[i]){
			vittu[i][st] = 1;
			++st;
			st = st%h[i];
		}
	}
	for(int i = 0; i < 1825; ++i){
		for(int j = 0; j < d; ++j){
			bool g = true;
			for(int k = 0; k < n; ++k){
				int hour = (i*d+j)%h[k];
				// /cout << hour << " vs " << h[k] << " " << r[k] << " " << t[k] << " " << vittu[k][hour] << endl;
				//cout << (hour > r[k] && hour < t[k]) << (hour > r[k] && t[k] < r[k]) << (hour < r[k] && t[k] < r[k]) << endl;
				if(vittu[k][hour]){
					g = false;
					break;
				}
			}
			if(g){
				cout << i*d+j << endl;
				return 0;
			}
		}
	}
	cout << "impossible\n";
	return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED