Submission #1094222

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094222		anhthi	Crocodile's Underground City (IOI11_crocodile)	C++14	100 / 100	307 ms	64456 KiB

crocodile

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)

template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }

template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }

template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }

int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}

const ll oo = (ll) 1e17;
const int inf = (ll) 2e9 + 7, mod = (ll) 998244353;

const int mxn = 2e5 + 5, mxm = MASK(5) + 1, LOG = 18;

void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }

struct Edge {
    int v, w;
    Edge(int _v, int _w) : v(_v), w(_w) {};
};
int n, m;
vector<Edge> g[mxn];

bool vis[mxn];
pair<int, int> a[4];
bool update(pair<int, int> &best, pair<int, int> &secondBest, pair<int, int> cur) {

    a[0] = cur;
    a[1] = best;
    a[2] = secondBest;
    sort(a, a + 3);

    best = a[0];
    int dist = secondBest.first;
    secondBest = a[1].second == best.second ? a[2] : a[1];

    return dist > secondBest.first;
}

int travel_plan(int N, int M, int R[][2], int L[], int K, int P[]) {

    n = N; m = M;
    forn(i, 0, m - 1) {
        int u = R[i][0];
        int v = R[i][1];
        g[u].pb(Edge(v, L[i]));
        g[v].pb(Edge(u, L[i]));
    }
    vector<pair<int, int>> best(n, mp(inf, inf)), secondBest;
    secondBest = best;
    forn(i, 0, K - 1) {
        int node = P[i];
        best[node] = secondBest[node] = mp(0, 0);
    }
    priority_queue<pair<int, int>> pq;
    forn(i, 0, n - 1) if (secondBest[i].first != inf) {
        pq.push(mp(0, i));
    }
    memset(vis, 0, sizeof vis);

    while (!pq.empty()) {
        pair<ll, int> top = pq.top(); pq.pop();
        int u = top.second; ll dist = -top.fi;

        if (vis[u]) continue;
        vis[u] = true;

        for (Edge i : g[u]) {
            int v = i.v;
            ll nxt = dist + i.w;

            if (update(best[v], secondBest[v], mp(nxt, u))) {
                pq.push(mp(-secondBest[v].first, v));
            }
        }
    }

    return secondBest[0].first;
}

//int main(void) {
//
//    ios_base::sync_with_stdio(0);
//    cin.tie(0); cout.tie(0);
//
//    #define TASK "task"
//    if (fopen(TASK".inp", "r")) {
//        freopen(TASK".inp", "r", stdin);
//        freopen(TASK".out", "w", stdout);
//    }
//
//    int n = 6, m = 6, k = 3;
//    int r[][2] = {{0, 1}, {0, 2}, {2, 5}, {2, 4}, {1, 4}, {1, 3}};
//    int l[] = {3, 3, 3, 5, 5, 3};
//    int p[] = {3, 4, 5};
//
//    cout << travel_plan(n, m, r, l, k, p);
//
//    return 0;
//}

• Subtask 1: 46 / 46
• Subtask 2: 43 / 43
• Subtask 3: 11 / 11