Submission #964247

#	Time	Username	Problem	Language	Result	Execution time	Memory
964247		GrindMachine	Senior Postmen (BOI14_postmen)	C++17	100 / 100	331 ms	69032 KiB

postmen

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://github.com/dolphingarlic/CompetitiveProgramming/blob/master/Baltic/Baltic%2014-postmen.cpp
https://codeforces.com/blog/entry/49035 (algorithm to find euler circuit)

*/

const int MOD = 1e9 + 7;
const int N = 5e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<pii> adj[N];
vector<int> ord;
vector<bool> vis(N);

void dfs1(int u){
    while(!adj[u].empty()){
        auto [v,id] = adj[u].back();
        adj[u].pop_back();
        if(vis[id]) conts;
        vis[id] = 1;
        dfs1(v);
    }
 
    ord.pb(u);
}
 
void solve(int test_case)
{
    int n,m; cin >> n >> m;
    rep1(i,m){
        int u,v; cin >> u >> v;
        adj[u].pb({v,i}), adj[v].pb({u,i});
    }
 
    dfs1(1);
    ord.pop_back();

    vector<vector<int>> ans;
    vector<int> curr;
    vector<bool> there(n+5);

    trav(u,ord){
        if(!there[u]){
            curr.pb(u);
            there[u] = 1;
            conts;
        }

        vector<int> cyc;
        cyc.pb(u);

        while(curr.back() != u){
            cyc.pb(curr.back());
            there[curr.back()] = 0;
            curr.pop_back();
        }

        reverse(all(cyc));
        ans.pb(cyc);
    }

    ans.pb(curr);

    trav(cyc,ans){
        trav(u,cyc){
            cout << u << " ";
        }

        cout << endl;
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 45 / 45