Submission #975052

#	Time	Username	Problem	Language	Result	Execution time	Memory
975052		hirayuu_oj	Strange Device (APIO19_strange_device)	C++17	100 / 100	378 ms	54036 KiB

strange_device

#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<n; i++)
#define all(x) x.begin(),x.end()
using ll=long long;
const ll INF=1LL<<61;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll n,A,B;
    cin>>n>>A>>B;
    ll g=__gcd(A,B+1);
    A/=g;
    ll rp=A*B;
    if((INF/A)/B==0LL){
        rp=INF;
    }
    vector<pair<ll,ll>> segs;
    rep(i,n){
        ll l,r;
        cin>>l>>r;
        r++;
        if(r-l>=rp){
            cout<<rp<<"\n";
            return 0;
        }
        l%=rp;
        r%=rp;
        if(l<r){
            segs.emplace_back(pair<ll,ll>(l,r));
        }
        if(l>r){
            segs.emplace_back(pair<ll,ll>(l,rp));
            segs.emplace_back(pair<ll,ll>(0,r));
        }
    }
    sort(all(segs));
    ll lf=0,ri=0;
    ll ans=0;
    for(auto &[nl,nr]:segs){
        if(nl<ri){
            ri=max(ri,nr);
        }
        else{
            ans+=ri-lf;
            lf=nl;
            ri=nr;
        }
    }
    ans+=ri-lf;
    cout<<ans<<"\n";
}

• 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