Submission #250459

#	Time	Username	Problem	Language	Result	Execution time	Memory
250459		DrumpfTheGodEmperor	Strange Device (APIO19_strange_device)	C++14	100 / 100	1002 ms	77500 KiB

strange_device

#include <bits/stdc++.h>
#define int long long
#define bp __builtin_popcountll
#define pb push_back
#define in(s) freopen(s, "r", stdin);
#define out(s) freopen(s, "w", stdout);
#define inout(s, end1, end2) freopen((string(s) + "." + end1).c_str(), "r", stdin),\
		freopen((string(s) + "." + end2).c_str(), "w", stdout);
#define fi first
#define se second
#define bw(i, r, l) for (int i = r - 1; i >= l; i--)
#define fw(i, l, r) for (int i = l; i < r; i++)
#define fa(i, x) for (auto i: x)
using namespace std;
const int mod = 1e9 + 7, inf = 1061109567;
const long long infll = 4557430888798830399;
const int MAX = 4e18 + 1;
int n, A, B;
int mul(int x, int y) {
	if ((MAX + y - 1) / y < x) return MAX;
	return x * y;
}
map<int, int> mp;
signed main() {
	#ifdef BLU
	in("blu.inp");
	#endif
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> A >> B;
	int d = A / __gcd(A, B + 1);
	//B * d is the cycle length.
	int cycleLen = mul(d, B);
	fw (i, 0, n) {
		int l, r;
		cin >> l >> r;
		if (r - l + 1 >= cycleLen) {
			cout << cycleLen << "\n";
			return 0;
		}
		//ELse it's either 1 or 2 segments.
		l %= cycleLen, r %= cycleLen;
		if (l > r) {
			//Divide into l to cycleLen - 1 and 0 to r.
			mp[l]++;
			mp[cycleLen]--;
			mp[0]++;
			mp[r + 1]--;
		} else {
			//Just 1 segment.
			mp[l]++;
			mp[r + 1]--;
		}
	}
	if (!mp.count(cycleLen)) mp[cycleLen] = 0;
	
	int curCnt = 0, lst = 0, ans = 0;
	fa (i, mp) {
		int coord = i.fi, cnt = i.se;
		if (curCnt > 0) ans += coord - lst;
		curCnt += cnt;
		lst = coord;
	}
	cout << ans;
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20
• Subtask 8: 30 / 30