Submission #932930

#	Time	Username	Problem	Language	Result	Execution time	Memory
932930		12345678	Strange Device (APIO19_strange_device)	C++17	35 / 100	583 ms	78768 KiB

strange_device

#include <bits/stdc++.h>

using namespace std;

#define ll unsigned long long

const int nx=1e6+5;
ll n, a, b, l[nx], r[nx], sm, p, mx, res, tmp;
set<pair<ll, ll>> s;

void add_range(ll x, ll y)
{
    x=x%p;
    y=y%p;
    if (y<x) y+=p;
    s.insert({x, min(p-1, y)});
    if (y>=p) s.insert({0, y-p});
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>a>>b;
    for (int i=1; i<=n; i++) cin>>l[i]>>r[i], mx=max(mx, r[i]-l[i]+1), sm+=(r[i]-l[i]+1);
    tmp=a/__gcd(a, b+1);
    if (tmp >= LLONG_MAX/b) return sm, 0;
    p=tmp*b;
    if (mx>=p) return cout<<p, 0;
    for (int i=1; i<=n; i++) add_range(l[i], r[i]);
    //for (auto [x, y]:s) cout<<"val "<<x<<' '<<y<<'\n';
    for (auto itr=s.begin(); itr!=s.end()&&next(itr)!=s.end();)
    {
        auto itr2=next(itr);
        pair<ll, ll> nw;
        if (itr2->first>itr->second+1) itr=itr2;
        else nw={itr->first, max(itr->second, itr2->second)}, s.erase(itr), s.erase(itr2), s.insert(nw), itr=s.find(nw);
    }
    for (auto [x, y]:s) res+=y-x+1;
    cout<<res;
}

/*
3 5 10
1 20
50 68
89 98

*/

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:24:20: warning: comparison of integer expressions of different signedness: 'int' and 'long long unsigned int' [-Wsign-compare]
   24 |     for (int i=1; i<=n; i++) cin>>l[i]>>r[i], mx=max(mx, r[i]-l[i]+1), sm+=(r[i]-l[i]+1);
      |                   ~^~~
strange_device.cpp:26:36: warning: left operand of comma operator has no effect [-Wunused-value]
   26 |     if (tmp >= LLONG_MAX/b) return sm, 0;
      |                                    ^~
strange_device.cpp:29:20: warning: comparison of integer expressions of different signedness: 'int' and 'long long unsigned int' [-Wsign-compare]
   29 |     for (int i=1; i<=n; i++) add_range(l[i], r[i]);
      |                   ~^~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 30