Submission #936566

#	Time	Username	Problem	Language	Result	Execution time	Memory
936566		azberjibiou	Longest Trip (IOI23_longesttrip)	C++17	100 / 100	11 ms	1416 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN=300;
int N;
bool Chk[mxN];
vector <int> makev(int a){
    vector <int> tmp;
    tmp.push_back(a);
    return tmp;
}
vector <int> makevlong(vector <int> v, int s, int e){
    vector <int> res;
    for(int i=s;i<=e;i++) res.push_back(v[i]);
    return res;
}
vector <int> solv_bipartite(vector <int> v1, vector <int> v2){
    if(!are_connected(v1, v2)){
        if(v1.size()>v2.size()) swap(v1, v2);
        return v2;
    }
    if(v1.size()>=2 && !are_connected(makev(v1[0]), makev(v1.back()))){
        if(are_connected(makev(v1.back()), makev(v2.back()))){
            while(v2.size()){
                v1.push_back(v2.back());
                v2.pop_back();
            }
            return v1;
        }
        else{
            for(int x : v1) v2.push_back(x);
            return v2;
        }
    }
    if(v2.size()>=2 && !are_connected(makev(v2[0]), makev(v2.back()))){
        if(are_connected(makev(v2.back()), makev(v1.back()))){
            while(v2.size()){
                v1.push_back(v2.back());
                v2.pop_back();
            }
            return v1;
        }
        else{
            for(int x : v2) v1.push_back(x);
            return v1;
        }
    }
    int s1=0, e1=(int)v1.size()-1;
    while(s1!=e1){
        int mid=(s1+e1)/2;
        if(are_connected(makevlong(v1, s1, mid), v2)) e1=mid;
        else s1=mid+1;
    }
    int s2=0, e2=(int)v2.size()-1;
    while(s2!=e2){
        int mid=(s2+e2)/2;
        if(are_connected(makev(v1[s1]), makevlong(v2, s2, mid))) e2=mid;
        else s2=mid+1;
    }
    vector <int> ans;
    for(int i=s1+1;i<v1.size();i++) ans.push_back(v1[i]);
    for(int i=0;i<=s1;i++) ans.push_back(v1[i]);
    for(int i=s2;i<v2.size();i++) ans.push_back(v2[i]);
    for(int i=0;i<s2;i++) ans.push_back(v2[i]);
    return ans;
}
vector <int> solv1(vector <int> v1);
vector <int> solv2(vector <int> v1, vector <int> v2);
vector <int> solv2(vector <int> v1, vector <int> v2){
    vector <int> nc;
    for(int i=0;i<N;i++) Chk[i]=false;
    for(int x : v1) Chk[x]=true;
    for(int x : v2) Chk[x]=true;
    for(int i=0;i<N;i++) if(!Chk[i]) nc.push_back(i);
    if(nc.empty()){
        return solv_bipartite(v1, v2);
    }
    else if(nc.size()==1){
        int p=nc.back();
        int l=v1.back(), r=v2.back();
        bool res1=are_connected(makev(p), makev(l)), res2=are_connected(makev(p), makev(r));
        if(res1 && res2){
            v1.push_back(p);
            while(v2.size()){
                v1.push_back(v2.back());
                v2.pop_back();
            }
            return v1;
        }
        else if(res1){
            v1.push_back(p);
            return solv_bipartite(v1, v2);
        }
        else if(res2){
            v2.push_back(p);
            return solv_bipartite(v1, v2);
        }
    }
    else{
        int p=nc[0], q=nc[1];
        int l=v1.back(), r=v2.back();
        bool res1=are_connected(makev(p), makev(l));
        if(!res1){
            v2.push_back(p);
            return solv2(v1, v2);
        }
        else{
            bool res2=are_connected(makev(p), makev(q)), res3=are_connected(makev(q), makev(r));
            if(res2 && res3){
                v1.push_back(p), v1.push_back(q);
                while(v2.size()){
                    v1.push_back(v2.back());
                    v2.pop_back();
                }
                return solv1(v1);
            }
            else if(res2 && !res3){
                v1.push_back(p), v1.push_back(q);
                return solv2(v1, v2);
            }
            else if(!res2 && res3){
                v1.push_back(p), v2.push_back(q);
                return solv2(v1, v2);
            }
            else{
                v1.push_back(q), v2.push_back(p);
                return solv2(v1, v2);
            }
        }
    }
}
vector <int> solv1(vector <int> v1){
    for(int i=0;i<N;i++) Chk[i]=false;
    for(int x : v1) Chk[x]=true;
    for(int i=0;i<N;i++) if(!Chk[i]){
        if(are_connected(makev(i), makev(v1.back()))) v1.push_back(i);
        else{
            vector <int> v2;
            v2.push_back(i);
            return solv2(v1, v2);
        }
    }
    return v1;
}
vector<int> longest_trip(int n, int D)
{
    N=n;
    return solv1(makev(0));
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> solv_bipartite(std::vector<int>, std::vector<int>)':
longesttrip.cpp:61:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |     for(int i=s1+1;i<v1.size();i++) ans.push_back(v1[i]);
      |                    ~^~~~~~~~~~
longesttrip.cpp:63:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for(int i=s2;i<v2.size();i++) ans.push_back(v2[i]);
      |                  ~^~~~~~~~~~
longesttrip.cpp: In function 'std::vector<int> solv2(std::vector<int>, std::vector<int>)':
longesttrip.cpp:70:18: warning: control reaches end of non-void function [-Wreturn-type]
   70 |     vector <int> nc;
      |                  ^~

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