Submission #543521

#	Time	Username	Problem	Language	Result	Execution time	Memory
543521		OttoTheDino	Strange Device (APIO19_strange_device)	C++17	100 / 100	1680 ms	100144 KiB

strange_device

#include <bits/stdc++.h>
using namespace std;
int main(){
    long long n, a, b, ans=0;
    cin>>n>>a>>b;
    if (log(a)+log(b)>log(__gcd(a,b+1))+log(1e18)){
        for (int i =0; i<n; ++i){
            long long li,ri;cin>>li>>ri;
            ans += ri-li+1;
        }
        cout<<ans<<endl;
        return 0;
    }
    long long s = a/__gcd(a,b+1)*b;
    set<pair<long long, long long>> st;
    for (int i = 0; i<n;++i){
        long long li, ri; cin >> li >> ri;
        if (ri-li>=s) st.insert({0,s-1});
        else if (ri%s<li%s){
            st.insert({0,ri%s});
            st.insert({li%s,s-1});
        }
        else st.insert({li%s,ri%s});
    }
    ans =s;
    long long x = -1;
    for (auto el : st) {
        ans -= max (el.first-x-1, 0LL);
        x = max (x, el.second);
    }
    ans -= s-1-x;
    cout << ans << endl;
    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