Submission #379172

#	Time	Username	Problem	Language	Result	Execution time	Memory
379172		Bill_00	Strange Device (APIO19_strange_device)	C++14	100 / 100	1755 ms	69320 KiB

strange_device

#include <bits/stdc++.h>
typedef long long ll;
#define N 20005
#define ff first
#define ss second
#define pb push_back
using namespace std;
ll gcd(ll a,ll b){
	while(a!=0 && b!=0){
		if(a>b){
			a=a%b;
		}
		else b=b%a;
	}
	return max(a,b);
}
vector<pair<pair<ll,ll>,pair<ll,ll> > >v;
int main(){
	ll n,a,b;
	cin >> n >> a >> b;
	ll k=gcd(a,(b+1));
	k=a/k;
	ll y=1e18;
	for(int i=1;i<=n;i++){
		ll l,r;
		cin >> l >> r;
		if(y/b>=k){
			if(k*b<=(r-l+1)){
				cout << k*b;
				return 0;
			}
		}
		ll x1=(l/b)%k;
		ll y1=l%b;
		ll x2=(r/b)%k;
		ll y2=r%b;
		// cout << x1 << ' ' << y1 << ' ' << x2 << ' ' << y2 << '\n';
		if((x1==x2 && y2<y1) || x2<x1){
			v.pb({{0,0},{x2,y2}});
			v.pb({{x1,y1},{k-1,b-1}});
		}
		else v.pb({{x1,y1},{x2,y2}});
	}
	sort(v.begin(),v.end());
	ll ans=0;
	pair<ll,ll>e={-1,-1};
	for(int i=0;i<v.size();i++){
		ll x1=v[i].ff.ff;
		ll y1=v[i].ff.ss;
		ll x2=v[i].ss.ff;
		ll y2=v[i].ss.ss;
		if(e.ff>x2 || (e.ff==x2 && e.ss>=y2)){
			continue;
		}
		if(x1>e.ff || (x1==e.ff && y1>e.ss)){
			ans+=((x2-x1)*b+y2-y1+1);
			e={x2,y2};
			continue;
		}
		ans+=((x2-e.ff)*b+y2-e.ss);
		e={x2,y2};
	}
	cout << ans;
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:47:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<long long int, long long int>, std::pair<long long int, long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |  for(int i=0;i<v.size();i++){
      |              ~^~~~~~~~~

• 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