Submission #631751

#	Time	Username	Problem	Language	Result	Execution time	Memory
631751		TranGiaHuy1508	Strange Device (APIO19_strange_device)	C++17	100 / 100	486 ms	53428 KiB

strange_device

/*
	Unknown's C++ Template (v3.2)
*/

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

#define int long long

using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using vi = vector<int>;
using vii = vector<ii>;
using vvi = vector<vi>;
using vvii = vector<vii>;
template <class T> using maxpq = priority_queue<T>;
template <class T> using minpq = priority_queue<T, vector<T>, greater<T>>;

#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mid ((l+r)>>1)
#define fi first
#define se second

#ifdef LOCAL
	#define debug(x) cout << #x << " = " << x << "\n";
#else
	#define debug(x) ;
#endif

template <class A, class B>
ostream& operator << (ostream& out, pair<A, B> x)
{ out << "(" << x.first << ", " << x.second << ")"; return out; }

template <class T>
ostream& operator << (ostream& out, vector<T> x){
	out << "[";
	for (int i=0; i<sz(x); i++) { out << (i ? ", " : "") << x[i]; }
	out << "]"; return out;
}

template <class T>
istream& operator >> (istream& in, vector<T> &x){
	for (auto &i: x) in >> i;
	return in;
}

const ld PI = acos(-1.0);
const int allmod[3] = {(int)1e9+7, 998244353, (int)1e9+9};
const int mod = allmod[0];
const int maxn = 2e5 + 64;
const ll inf = 1e18;
const ld eps = 1e-6;
const int multitest = 0;

int mult(int a, int b){
	if ((a > 4e18 / b) || (b > 4e18 / a)) return 4e18;
	return a * b;
}

void main_program(){
	int n, A, B; cin >> n >> A >> B;
	int g = __gcd(A, B + 1);
	int m = A / g;

	int md = mult(m, B);
	vii crr;

	for (int i = 0; i < n; i++){
		int L, R; cin >> L >> R;
		// L = a * md + b
		// R = c * md + d
		int a = L / md, b = L % md, c = R / md, d = R % md;
		debug(a); debug(b); debug(c); debug(d);
		if (b <= d){
			if (a == c) crr.emplace_back(b, d);
			else{
				cout << md << "\n";
				return;
			}
		}
		else{
			if (a + 1 == c){
				crr.emplace_back(b, md - 1);
				crr.emplace_back(0, d);
			}
			else{
				cout << md << "\n";
				return;
			}
		}
	}

	sort(all(crr)); debug(crr);
	int lim = 0, res = 0;
	for (auto [i, j]: crr){
		lim = max(lim, i);
		res += max(0LL, j - lim + 1);
		lim = max(lim, j+1);
	}
	cout << res << "\n";
}

void pre_main(){

}

signed main(){
	#ifdef LOCAL
		auto stime = chrono::high_resolution_clock::now();
	#endif
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	#ifndef ONLINE_JUDGE
		if (fopen(".inp", "r")){
			freopen(".inp", "r", stdin);
			freopen(".out", "w", stdout);
		}
	#endif
	int t = 1; if (multitest) cin >> t;
	pre_main();
	while (t--) main_program();
	#ifdef LOCAL
		auto etime = chrono::high_resolution_clock::now();
		auto duration = chrono::duration_cast<chrono::milliseconds>(etime-stime).count();
		cout << "\n[" << duration << "ms]\n";
	#endif
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:117:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |    freopen(".inp", "r", stdin);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~
strange_device.cpp:118:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |    freopen(".out", "w", stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

• 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