Submission #1029115

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029115		YassineBenYounes	Longest Trip (IOI23_longesttrip)	C++17	40 / 100	981 ms	1368 KiB

longesttrip

#include<bits/stdc++.h>
#include<chrono>
#include<random>
#include "longesttrip.h"
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, -1, 1};
#define endl "\n"
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd  pair<double,double>
#define vdd  vector<pdd>
#define speed ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pbds tree<pii, null_type, less<pii>,rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

////////////////////Only Clear Code//////////////////////////
 
void usaco_problem(){
    freopen("milkvisits.in", "r", stdin);
    freopen("milkvisits.out", "w", stdout);
}
 
void init(){
    #ifndef ONLINE_JUDGE
 
freopen("input.txt", "r", stdin);
 
freopen("output.txt", "w", stdout);
 
#endif // ONLINE_JUDGE
}
const int mx = 260;
const int LOG = 22;
const int inf = 1e9;
const ll mod = 998244353;
const int sq = 320;

vi graph[mx];

bool vis[mx];

vi ans;

void dfs(int node){
    vis[node] = 1;
    ans.pb(node);
    vi v;
    for(int adj : graph[node]){
        if(vis[adj])continue;
        v.pb(adj);
    }
    int s = v.size();
    if(s == 0)return;
    int ind = rng() % s;
    dfs(v[0]);
}
/*
bool are_connected(vi a, vi b){
    return 1;
}*/

vi longest_trip(int N, int D){
    if(D == 3){
        vi res;
        for(int i = 0; i < N;i++){
            res.pb(i);
        }
        return res;
    }
    else{
        for(int i = 0; i < N;i++){
            graph[i].clear();
        }
        for(int i = 0; i < N;i++){
            for(int j = i+1;j < N;j++){
                if(are_connected({i}, {j})){
                    graph[i].pb(j);
                    graph[j].pb(i);
                }
            }
        }
        vi res;
        for(int i = 0; i < N;i++){
            memset(vis, 0, sizeof vis);
            ans.clear();
            dfs(i);
            if(ans.size() > res.size())res = ans;
        }
        return res;
    }
}

/*
int32_t main(){
    init();
    speed;
    vi a = longest_trip(5, 2);
    cout << a.size() << endl;
    for(int x : a){
        cout << x << " ";
    }
    cout << endl;
}*/
/*
    NEVER GIVE UP!
    DOING SMTHNG IS BETTER THAN DOING NTHNG!!!
    Your Guide when stuck:
    - Continue keyword only after reading the whole input
    - Don't use memset with testcases
    - Check for corner cases(n=1, n=0)
    - Check where you declare n(Be careful of declaring it globally and in main)
*/

Compilation message (stderr)

longesttrip.cpp: In function 'void dfs(int)':
longesttrip.cpp:72:9: warning: unused variable 'ind' [-Wunused-variable]
   72 |     int ind = rng() % s;
      |         ^~~
longesttrip.cpp: In function 'void usaco_problem()':
longesttrip.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("milkvisits.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen("milkvisits.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp: In function 'void init()':
longesttrip.cpp:44:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 | freopen("input.txt", "r", stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
longesttrip.cpp:46:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 | freopen("output.txt", "w", stdout);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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