Submission #1273026

#	Time	Username	Problem	Language	Result	Execution time	Memory
1273026		pvpro	Cyberland (APIO23_cyberland)	C++20	100 / 100	1760 ms	207096 KiB

cyberland

#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <cstdio>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <algorithm>
#include <cmath>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <chrono>
#include <random>
#include <complex>
#include <numeric>
#include <assert.h>
#include <functional>
#include <climits>
#include <cstring>
#include <iterator>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

using ll = long long;
using ld = long double;
using ushort = unsigned short;

#ifndef LOCAL
#define endl "\n"
#endif
#define f first
#define s second
#define vec vector
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
template<typename T1, typename T2>
istream& operator>> (istream &in, pair<T1, T2> &p) { in >> p.f >> p.s; return in; }
template<typename T1, typename T2>
ostream& operator<< (ostream &out, pair<T1, T2> p) { out << "(" << p.f << " " << p.s << ")"; return out; }
#define printv(v) cerr << #v << " "; for (auto &x : v) { cerr << x << " "; } cerr << endl;
#define printvv(v) cerr << #v << " "; for (auto &x : v) { for (auto &y : x) { cerr << y << " "; } cerr << endl; }
#define debug(x) cerr << #x << " " << x << endl;

template<typename T>
istream& operator>> (istream &in, vector<T> &v) {
    for (auto &x : v) {
        in >> x;
    }
    return in;
}
template<typename T>
ostream& operator<< (ostream &out, vector<T> v) {
    for (auto &x : v) {
        out << x << " ";
    }
    return out;
}
template<typename T>
void operator-=(vector<T> &v, int delta) {
    for (auto &x : v) {
        x -= delta;
    }
}
template<typename T>
void operator+=(vector<T> &v, int delta) {
    for (auto &x : v) {
        x += delta;
    }
}

mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

struct DSU {
    vector<int> pr;
    DSU(int n) {
        pr.resize(n);
        iota(all(pr), 0);
    }
    int get(int v) {
        if (pr[v] != v) {
            pr[v] = get(pr[v]);
        }
        return pr[v];
    }
    bool unite(int a, int b) {
        a = get(a);
        b = get(b);
        if (a == b) {
            return false;
        }
        pr[a] = b;
        return true;
    }
};

double solve(int n, int m, int k, int h, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
    vector<vector<pii>> graph(n);
    for (int i = 0; i < m; ++i) {
        graph[x[i]].pb(mp(y[i], c[i]));
        graph[y[i]].pb(mp(x[i], c[i]));
    }
    queue<int> qq;
    qq.push(0);
    vector<int> ok(n);
    bool was = false;
    while (!qq.empty()) {
        int v = qq.front();
        qq.pop();
        ok[v] = true;
        if (v == h) {
            was = true;
            continue;
        }
        for (auto &pu : graph[v]) {
            if (!ok[pu.f]) {
                ok[pu.f] = 1;
                qq.push(pu.f);
            }
        }
    }
    if (!was) {
        return -1;
    }
    priority_queue<pair<int, pair<ld, int>>> q;
    vector<ld> d(n * min(101, (k + 1)), 1e18);
    vector<int> marked(n * min(101, (k + 1)));
    q.push(mp(0, mp(0, 0)));
    d[0] = 0;
    for (int i = 1; i < n; ++i) {
        if (ok[i]) {
            if (k > 100 && arr[i] == 2) {
                int e = 2e9 + 11;
                for (auto &x : graph[i]) {
                    if (x.f == h) {
                        continue;
                    }
                    if (arr[x.f] == 2) {
                        e = min(e, x.s);
                    } else {
                        e = min(e, x.s * 2);
                    }
                }
                q.push(mp(0, mp(-e, i)));
                d[i] = e;
            }
            if (arr[i] == 0) {
                q.push(mp(0, mp(0, i)));
                d[i] = 0;
            }
        }
    }
    k = min(k, 100);
    while (!q.empty()) {
        int vk = q.top().s.s;
        int v = vk % n;
        q.pop();
        if (marked[vk]) {
            continue;
        }
        marked[vk] = true;
        if (v == h) {
            continue;
        }
        for (auto &pu : graph[v]) {
            if (d[pu.f + vk - v] > d[vk] + pu.s) {
                d[pu.f + vk - v] = d[vk] + pu.s;
                q.emplace(v - vk, mp(-d[pu.f + vk - v], pu.f + vk - v));
            }
            if (vk + n < n * (k + 1) && arr[pu.f] == 2) {
                if (d[pu.f + vk - v + n] > (d[vk] + pu.s) / 2) {
                    d[pu.f + vk - v + n] = (d[vk] + pu.s) / 2;
                    q.emplace(v - vk - n, mp(-d[pu.f + vk - v + n], pu.f + vk - v + n));
                }
            }
        }
    }
    ld ans = d[h];
    for (int j = 0; j <= k; ++j) {
        ans = min(ans, d[h + j * n]);
    }
    return ans;
}

#ifdef LOCAL
int main() {
    freopen("in.txt", "r", stdin);
    int T;
    assert(1 == scanf("%d", &T));
    while (T--){
        int N,M,K,H;
        assert(4 == scanf("%d %d %d\n%d", &N, &M, &K, &H));
        std::vector<int> x(M);
        std::vector<int> y(M);
        std::vector<int> c(M);
        std::vector<int> arr(N);
        for (int i=0;i<N;i++)
            assert(1 == scanf("%d", &arr[i]));
        for (int i=0;i<M;i++)
            assert(3 == scanf("%d %d %d", &x[i], &y[i], &c[i]));
        printf("%.12lf\n", solve(N, M, K, H, x, y, c, arr));
    }
}
#endif

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