Submission #744137

#	Time	Username	Problem	Language	Result	Execution time	Memory
744137		Kenjikrab	Strange Device (APIO19_strange_device)	C++14	100 / 100	578 ms	52808 KiB

strange_device

#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
#define db double
using namespace std;
int const n_max=1e6+10;
int gcd(int a,int b)
{
    if(b%a==0)return a;
    return gcd(b%a,a);
}
int st[n_max];
int en[n_max];
signed main()
{
    cin.tie(nullptr)->sync_with_stdio(false);
    int n,A,B;
    cin>>n>>A>>B;
    int h=gcd(min(A,B+1),max(A,B+1));
    int sum=0;
    for(int i=0;i<n;i++)
    {
        cin>>st[i]>>en[i];
        sum+=en[i]-st[i]+1;
    }
    int val=A/h;
    if((db) en[n-1]/val<= (db) B)
    {
        cout<<sum;
        return 0;
    }
    val*=B;
    vector<pii> keep;
    for(int i=0;i<n;i++)
    {
        if(en[i]-st[i]+1>=val)
        {
            cout<<val;
            return 0;
        }
        st[i]%=val;
        en[i]%=val;
        if(en[i]>=st[i])
        {
            keep.push_back({st[i],en[i]});
        }
        else
        {
            keep.push_back({st[i],val-1});
            keep.push_back({0,en[i]});
        }
    }
    sort(keep.begin(),keep.end());
    sum=0;
    int maxi=-1;
    for(int i=0;i<keep.size();i++)
    {
        int u=keep[i].fi;
        int v=keep[i].se;
        if(v<=maxi)continue;
        sum+=v-max(u,maxi+1)+1;
        maxi=max(v,maxi);
    }
    cout<<sum;
    return 0;
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:58:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for(int i=0;i<keep.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