Submission #1038175

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038175		aymanrs	Longest Trip (IOI23_longesttrip)	C++17	60 / 100	873 ms	1116 KiB

longesttrip

#include "longesttrip.h"
#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
bool g[300][300] = {{false}};
bool ej[256] = {false};
pair<vector<int>,vector<int>> fl(const vector<int>& V){
    memset(ej, 0, sizeof(ej));
    queue<int> q;q.push(V[0]);
    ej[V[0]]=true;
    vector<int> a;a.push_back(V[0]);
    while(!q.empty()){
        int t = q.front();
        q.pop();
        for(int j : V){
            if(g[t][j] && !ej[j]){
                ej[j]=true;
                q.push(j);
                a.push_back(j);
            }
        }
    }
    vector<int> b, c;
    if(a.size()<V.size()){
        for(int i : V) if(!ej[i]) b.push_back(i);
        return {a,b};
    }
    int i, j;
    for(i = 0;i < V.size();i++){
        for(j = i+1;j < V.size();j++){
            if(!g[V[i]][V[j]]) goto hoho;
        }
    }
    hoho:
    if(i >= V.size() || j >= V.size()) return {a, {}};
    a.clear();
    i=V[i];j=V[j];
    for(int k : V){
        if(k==i||k==j) continue;
        if(!g[k][j]) a.push_back(k);
        else if(!g[k][i]) c.push_back(k);
        else {
            b.push_back(k);
        }
    }
    if(b.empty()){
        a.push_back(i);
        for(int& k : a){
            for(int& l : c){
                if(g[k][l]){
                    swap(k, a.back());
                    swap(l, c[0]);
                    c.push_back(j);
                    for(int x : c) a.push_back(x);
                    return {a, {}};
                }
            }
        }
    }
    auto L = fl(b);
    if(L.second.empty()){
        a.push_back(i);
        for(int k : L.first) a.push_back(k);
        a.push_back(j);
        for(int k : c) a.push_back(k);
        return {a, {}};
    } else {
        if(a.empty()){
            L.first.push_back(i);
            for(int k : L.second) L.first.push_back(k);
            L.first.push_back(j);
            for(int k : c) L.first.push_back(k);
            return {L.first, {}};
        }
        if(g[a[0]][L.first[0]]){
            a.push_back(i);
            swap(a.back(), a[0]);
            for(int k : L.first) a.push_back(k);
            for(int k : a) L.second.push_back(k);
            L.second.push_back(j);
            for(int k : c) L.second.push_back(k);
            return {L.second, {}};
        } else {
            a.push_back(i);
            swap(a.back(), a[0]);
            for(int k : L.second) a.push_back(k);
            for(int k : a) L.first.push_back(k);
            L.first.push_back(j);
            for(int k : c) L.first.push_back(k);
            return {L.first, {}};
        }
    }

}
std::vector<int> longest_trip(int N, int D)
{
    vector<int> V;
    for(int i = 0;i < N;i++) for(int j = 0;j < N;j++) g[i][j] = false;
    for(int i = 0;i < N;i++){
        V.push_back(i);
        for(int j = i+1;j < N;j++){
            if(are_connected({i}, {j})){
                g[i][j]=g[j][i]=true;
            }
        }
    }
    auto L = fl(V);
   if(L.first.size()>=L.second.size()) return L.first;
   return L.second;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::pair<std::vector<int>, std::vector<int> > fl(const std::vector<int>&)':
longesttrip.cpp:30:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for(i = 0;i < V.size();i++){
      |               ~~^~~~~~~~~~
longesttrip.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         for(j = i+1;j < V.size();j++){
      |                     ~~^~~~~~~~~~
longesttrip.cpp:36:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     if(i >= V.size() || j >= V.size()) return {a, {}};
      |        ~~^~~~~~~~~~~
longesttrip.cpp:36:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     if(i >= V.size() || j >= V.size()) return {a, {}};
      |                         ~~^~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 19.999999998 / 60