Submission #711039

#	Time	Username	Problem	Language	Result	Execution time	Memory
711039		ToroTN	Sure Bet (CEOI17_sure)	C++14	100 / 100	78 ms	3812 KiB

sure

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
int n,st,md,ed;
double a,b,ans=0;
vector<double> v1,v2;
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%lf%lf",&a,&b);
        v1.pb(-a),v2.pb(-b);
    }
    v1.pb(-1e9),v2.pb(-1e9);
    sort(v1.begin(),v1.end());
    sort(v2.begin(),v2.end());
    for(int i=1;i<=n;i++)v1[i]=-v1[i],v2[i]=-v2[i];
    for(int i=2;i<=n;i++)v1[i]=v1[i-1]+v1[i],v2[i]=v2[i-1]+v2[i];
    v1[0]=0,v2[0]=0;
    /*for(int i=0;i<=n;i++)
    {
        printf("%lf %lf\n",v1[i],v2[i]);
    }*/
    for(int i=1;i<=2*n;i++)
    {
        st=0,ed=i;
        while(ed>=st)
        {
            md=(st+ed)/2;
            if(md>n)
            {
                ed=md-1;
                continue;
            }
            if(i-md>n)
            {
                st=md+1;
                continue;
            }
            ans=max(ans,min(v1[md],v2[i-md])-i);
            if(v1[md]<=v2[i-md])
            {
                st=md+1;
            }else
            {
                ed=md-1;
            }
        }
        //printf("i=%d\n",i);
        //printf("%d %d %d\n",st,md,ed);
        st-=1;
        if(st>=0&&st<=n&&i-st>=0&&i-st<=n)
        {
            ans=max(ans,min(v1[st],v2[i-st])-i);
        }
        st+=1;
        if(st>=0&&st<=n&&i-st>=0&&i-st<=n)
        {
            ans=max(ans,min(v1[st],v2[i-st])-i);
        }
        st-=1;
        if(st>=0&&st<=n&&i-st>=0&&i-st<=n)
        {
            ans=max(ans,min(v1[st],v2[i-st])-i);
        }
    }
    printf("%.4lf\n",ans);
}

Compilation message (stderr)

sure.cpp: In function 'int main()':
sure.cpp:9:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
sure.cpp:12:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         scanf("%lf%lf",&a,&b);
      |         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40