Submission #984426

#	Time	Username	Problem	Language	Result	Execution time	Memory
984426		SmuggingSpun	Strange Device (APIO19_strange_device)	C++14	100 / 100	439 ms	71832 KiB

strange_device

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
typedef long long ll;
const int lim = 1e6 + 5;
const ll INF = 1e18;
int n;
ll A, B, S = 0, l[lim], r[lim];
namespace sub1{
	void solve(){
		map<pair<ll, ll>, bool>cnt;
		for(int i = 0; i < n; i++){
			for(ll j = l[i]; j <= r[i]; j++){
				cnt[make_pair((j + j / B) % A, j % B)] = true;
			}
		}
		cout << cnt.size();
	}
}
ll next_mod(ll current, ll d, ll r){
	ll R = current % d;
	if(R < r){
		return current + r - R;
	}
	return current + d - R + r;
}
ll prev_mod(ll current, ll d, ll r){
	ll R = current % d;
	if(R > r){
		return current - R + r;
	}
	return current - d + r - R;
}
namespace sub2{
	void solve(){
		ll cnt_cycle = A / __gcd(A, B + 1), init_cnt = (prev_mod(r[0], B, l[0] % B) - l[0]) / B + 1;
		if(l[0] % B < r[0] % B){
			cout << min(init_cnt, cnt_cycle) * (r[0] % B - l[0] % B + 1) + min(init_cnt - 1, cnt_cycle) * (B - r[0] % B - 1 + l[0] % B);
		}
		else{
			cout << min(init_cnt, cnt_cycle) * (B - l[0] % B + r[0] % B + 1) + min(init_cnt - 1, cnt_cycle) * (l[0] % B + B - r[0] % B - 1);
		}
	}
}
namespace sub4{
	void solve(){
		if(~A & 1){
			A >>= 1LL;
		}
		vector<pair<ll, ll>>range;
		for(int i = 0; i < n; i++){
			if(r[i] - l[i] + 1 >= A){
				return void(cout << A);
			}
			if((l[i] %= A) <= (r[i] %= A)){
				range.emplace_back(l[i], r[i]);
			}
			else{
				range.emplace_back(l[i], A - 1);
				range.emplace_back(0, r[i]);
			}
		}
		sort(range.begin(), range.end());
		ll ans = range[0].second - range[0].first + 1, pre = range[0].second;
		for(int i = 1; i < range.size(); i++){
			if(range[i].second > pre){
				ans += range[i].second - max(range[i].first, pre + 1) + 1;
				pre = range[i].second;
			}
		}
		cout << ans;
	}
}
namespace sub35678{
	void solve(){
		map<ll, int>cnt;
		if(INF / A < (B + 1) / __gcd(A, B + 1)){
			return void(cout << S);
		}
		ll cyc = A / __gcd(A, B + 1) * B;
		vector<pair<ll, ll>>range;
		for(int i = 0; i < n; i++){
			if(r[i] - l[i] + 1 >= cyc){
				return void(cout << cyc);
			}
			if((l[i] %= cyc) <= (r[i] %= cyc)){
				range.emplace_back(l[i], r[i]);
			}
			else{
				range.emplace_back(l[i], cyc - 1);
				range.emplace_back(0, r[i]);
			}
		}
		sort(range.begin(), range.end());
		ll ans = range[0].second - range[0].first + 1, pre = range[0].second;
		for(int i = 1; i < range.size(); i++){
			if(range[i].second > pre){
				ans += range[i].second - max(range[i].first, pre + 1) + 1;
				pre = range[i].second;
			}
		}
		cout << ans;
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	cin >> n >> A >> B;
	for(int i = 0; i < n; i++){
		cin >> l[i] >> r[i];
		S += r[i] - l[i] + 1;
	}
	if(S <= 1000000){
		sub1::solve();
	}
	else if(n == 1){
		sub2::solve();
	}
	else if(B == 1){
		sub4::solve();
	}
	else{
		sub35678::solve();
	}
}

Compilation message (stderr)

strange_device.cpp: In function 'void sub4::solve()':
strange_device.cpp:65:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   for(int i = 1; i < range.size(); i++){
      |                  ~~^~~~~~~~~~~~~~
strange_device.cpp: In function 'void sub35678::solve()':
strange_device.cpp:96:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |   for(int i = 1; i < range.size(); i++){
      |                  ~~^~~~~~~~~~~~~~
strange_device.cpp: In function 'int main()':
strange_device.cpp:108:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |   freopen(taskname".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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