Submission #948916

#	Time	Username	Problem	Language	Result	Execution time	Memory
948916		kim	Longest Trip (IOI23_longesttrip)	C++17	100 / 100	11 ms	860 KiB

longesttrip

#include "longesttrip.h"
#include<bits/stdc++.h>
using namespace std;
#define eb emplace_back
#define sz(x) (int)(x).size()

#define ask are_connected

std::vector<int> longest_trip(int N, int D)
{
    vector<int> v1,v2;
    v1.eb(0), v2.eb(1);
    int cur=1;
    for(int i=2;i<N;++i){
        if(ask({v1.back()},{i})) v1.eb(i), cur=i;
        else if(cur!=i-1||ask({v2.back()},{i})) v2.eb(i);
        else{
            while(sz(v2)) v1.eb(v2.back()), v2.pop_back();
            v2.eb(i);
            cur=i;
        }
    }
    if(!ask(v1,v2)) return sz(v1)>sz(v2)?v1:v2;
    if(ask({v1.back()},{v2.back()})){
        for(int i=sz(v2)-1;i>=0;--i) v1.eb(v2[i]);
        return v1;
    }
    if(ask({v1.front()},{v2.back()})){
        for(auto &e:v1) v2.eb(e);
        return v2;
    }
    if(ask({v1.back()},{v2.front()})){
        for(auto &e:v2) v1.eb(e);
        return v1;
    }
    int p1,p2;
    vector<int> tmp;
    {
        int l=0,r=sz(v1)-1;
        while(l<r){
            int mid=l+r>>1;
            tmp.clear();
            for(int i=0;i<=mid;++i) tmp.eb(v1[i]);
            if(ask(tmp,v2)) r=mid;
            else l=mid+1;
        }
        p1=l;
    }{
        int l=0,r=sz(v2)-1;
        while(l<r){
            int mid=l+r>>1;
            tmp.clear();
            for(int i=0;i<=mid;++i) tmp.eb(v2[i]);
            if(ask(tmp,{v1[p1]})) r=mid;
            else l=mid+1;
        }
        p2=l;
    }
    tmp.clear();
    for(int i=p1+1;i<sz(v1);++i) tmp.eb(v1[i]);
    for(int i=0;i<=p1;++i) tmp.eb(v1[i]);
    for(int i=p2;i<sz(v2);++i) tmp.eb(v2[i]);
    for(int i=0;i<p2;++i) tmp.eb(v2[i]);
    return tmp;
}
/*
2
5 1
1
1 1
0 0 1
0 0 0 1
4 1
1
0 0
0 0 1
*/

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:41:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |             int mid=l+r>>1;
      |                     ~^~
longesttrip.cpp:51:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |             int mid=l+r>>1;
      |                     ~^~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 60 / 60