Submission #1000819

#	Time	Username	Problem	Language	Result	Execution time	Memory
1000819		underwaterkillerwhale	Cyberland (APIO23_cyberland)	C++17	0 / 100	3073 ms	30468 KiB

cyberland

#include "cyberland.h"

#include <bits/stdc++.h>
#define se              second
#define fs              first
#define mp              make_pair
#define pb              push_back
#define ll              long long
#define ii              pair<ll,ll>
#define ld              long double
#define SZ(v)           (int)v.size()
#define ALL(v)          v.begin(), v.end()
#define bit(msk, i)     ((msk >> i) & 1)
#define iter(id, v)     for(auto id : v)
#define rep(i,m,n)      for(int i=(m); i<=(n); i++)
#define reb(i,m,n)      for(int i=(m); i>=(n); i--)

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now().time_since_epoch().count());
ll Rand(ll l, ll r) { return uniform_int_distribution<ll> (l, r)(rd); }

const int N  = 1e5 + 7;
const int Mod = 1e9 +7;
const int szBL = 50;
const ll INF = 1e13;
const int BASE = 137;

struct toEdge {
    int v;
    ll w;
};

int n, m, K, H;
int a[N];
vector<toEdge> ke[N];
double dp[N][35];
bool canGo[N];

void BFS () {
    queue<int> Q;
    Q.push(1);
    canGo[1] = 1;
    while (!Q.empty()) {
        int u = Q.front();
        Q.pop();
        iter (&id, ke[u]) {
            if (canGo[id.v] == 0) {
                canGo[id.v] = 1;
                if (id.v != H)
                    Q.push(id.v);
            }
        }
    }
}
double algo () {
    BFS();
    if (canGo[H] == 0) {
        return -1;
    }
    struct Data {
        ll u, k;
        long double val;
    };
    struct cmp {
        bool operator () (Data A, Data B) { return A.val > B.val; }
    };
    priority_queue<Data, vector<Data>, cmp> pq;
    rep (i, 1, n) rep (k, 0, min(K, 30)) dp[i][k] = INF;
    rep (i, 1, n)  if ((i == 1) || (a[i] == 0 && canGo[i])) {
        pq.push({i, 0, 0});
        dp[i][0] = 0;
    }
    while (!pq.empty()) {
        Data cur = pq.top();
        int u = cur.u, k = cur.k;
        pq.pop();
        iter (&id, ke[u]) {
            int v = id.v;
            ll w = id.w;
            if (a[v] == 0) continue;
            else {
                if (dp[v][k] > dp[u][k] + w) {
                    dp[v][k] = dp[u][k] + w;
                    pq.push({v, k, dp[v][k]});
                }
                if (a[v] == 2 && k < 30 && dp[v][k + 1] > (dp[u][k] + w) / 2) {
                    dp[v][k + 1] = (dp[u][k] + w) / 2;
                    pq.push({v, k + 1, dp[v][k + 1]});
                }
            }
        }
    }
    double res = INF;
    rep (i, 0, min(K, 30)) {
        res = min(res, dp[H][i]);
    }
    return res;
}

double solve (int _n, int _m, int _K, int _H, vector<int> _U, vector<int> _V, vector<int> _W, vector<int> _A) {
//void solution() {
//    cin >> n >> m >> K >> H;
//    rep (i, 1, n) cin >> a[i];
//    rep (i, 1, m) {
//        int u, v, w;
//        cin >> u >> v>> w;
//        ++u, ++v;
//        ke[u].push_back({v, w});
//        ke[v].push_back({u, w});
//    }
    n = _n;
    m = _m;
    K = _K;
    H = _H;
    ++H;
    rep (i, 1, n) {
        a[i] = _A[i - 1];
    }
    rep (i, 0, m - 1) {
        int u = _U[i], v = _V[i], w = _W[i];
        ++u, ++v;
        ke[u].push_back({v, w});
        ke[v].push_back({u, w});
    }
    return algo();
}

//#define file(name) freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);
//int main () {
//    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
////    file ("c");
//    int num_Test = 1;
//    cin >> num_Test;
//    while (num_Test--)
//        solution();
//}
/*
1
3 2 30
2
1 2 1
1 2 12
2 0 4




3 2
0 1 5
0 2 5
1
1 2

*/

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3