Submission #1076306

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076306		c2zi6	Longest Trip (IOI23_longesttrip)	C++17	5 / 100	912 ms	1216 KiB

longesttrip

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "longesttrip.h"

bool commonedge(VI a, VI b) {
    return !are_connected(a, b);
}
bool commonedge(int u, int v) {
    return !are_connected({u}, {v});
}

int n;
VVI gp;
VVI gpmatrix;

int mex(VI a) {
    set<int> st;
    for (int x : a) st.insert(x);
    for (int i = 0; i < 2e9; i++) if (st.count(i) == 0) return i;
    return -1;
}

VI longest_trip(int N, int D) {
    /*if (D >= 2) {*/
    /*    int n = N;*/
    /*    VI group(n, -1);*/
    /*    int last = 0;*/
    /*    rep(u, n) if (group[u] == -1) {*/
    /*        group[u] = last;*/
    /*        rep(v, n) if (group[v] == -1) {*/
    /*            if (commonedge({u}, {v})) group[v] = last;*/
    /*        }*/
    /*        last++;*/
    /*    }*/
    /*    VVI comp(last);*/
    /*    rep(u, n) comp[group[u]].pb(u);*/
    /*    sort(all(comp), [&](const VI& a, const VI& b){return a.size() > b.size();});*/
    /*    int prev = -1;*/
    /*    VI ans;*/
    /*    rep(_, 3) {*/
    /*        rep(i, last) {*/
    /*            assert(comp[i].size() <= 2);*/
    /*            if (comp[i].size() && i != prev) {*/
    /*                ans.pb(comp[i].back());*/
    /*                comp[i].pop_back();*/
    /*                prev = i;*/
    /*            }*/
    /*        }*/
    /*    }*/
    /*    rep(i, last) assert(comp[i].size() == 0);*/
    /*    return ans;*/
    /*}*/
    n = N;
    gp = VVI(n);
    gpmatrix = VVI(n, VI(n));
    replr(u, 0, n-1) {
        replr(v, u+1, n-1) {
            if (commonedge(u, v)) {
                gp[u].pb(v);
                gp[v].pb(u);
                gpmatrix[u][v] = gpmatrix[v][u] = true;
                /*cout << "found edge " << u << " " << v << endl;*/
            }
        }
    }
    VI vis(n);
    VI group(n, -1);
    int l = 0;
    rep(u, n) {
        VI ret;
        for (int v : gp[u]) if (group[v] != -1) ret.pb(group[v]);
        group[u] = mex(ret);
        setmax(l, group[u]+1);
    }
    VVI comp(l);
    rep(u, n) comp[group[u]].pb(u);

    mt19937 rng(chrono::steady_clock().now().time_since_epoch().count());
    for (VI& a : comp) shuffle(all(a), rng);

    VI ans;

    int prev = -1;
    while (true) {
        bool ayo = false;
        for (VI& a : comp) {
            VI nw;
            for (int x : a) {
                if (prev != -1 && gpmatrix[x][prev]) {
                    nw.pb(x);
                    continue;
                }
                ans.pb(x);
                prev = x;
                ayo = true;
            }
            a = nw;
        }
        if (ayo == false) break;
    }
    return ans;

    /*vis = VI(l);*/
    /*for (VI vec : comp) {*/
    /*    for (int x : vec) cout << x << " ";*/
    /*    cout << endl;*/
    /*}*/

    return {-1488};
}

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