Submission #1094134

#	Time	Username	Problem	Language	Result	Execution time	Memory
1094134		RiverFlow	Cyberland (APIO23_cyberland)	C++17	97 / 100	646 ms	54424 KiB

cyberland

#include "cyberland.h"

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b or a == -1) { a = b; return 1; } return 0;
}

const int N = (int)2e5 + 9;
const int mod = (int)1e9 + 7;


struct edge {
    int u, v, w;
    edge () {};
    edge (int _u, int _v, int _w) {
        u = _u, v = _v, w = _w;
    }
} e[N];

int n, m, k, h, ar[N];
vec<pair<int, int>> g[N];

#define ld double
const ld esp = (ld)1e-9;
namespace SUB1 {
const int K = 32;
ld dis[N][K];
ld sol() {
    FOR(i, 0, n - 1)
    FOR(j, 0, k) dis[i][j] = -1;
    dis[0][0] = 0;
    #define T pair<ld, ii>
    priority_queue<T, vec<T>, greater<T>> pq;
    pq.push(_mp(0, _mp(0, 0)));
    while (!pq.empty()) {
        auto x = pq.top(); pq.pop();
        int u = x.se.fi;
        int t = x.se.se;
//        cout<<u<<' '<<t<<' '<<dis[u][t]<<nl;
        if (u == h) continue ;
        if (abs(x.fi - dis[u][t]) > esp) continue ;
        for(auto j : g[u]) {
            int v = j.fi;
            // khong dung
            if (ar[v] == 0) {
                if (dis[v][0]==-1){
                    dis[v][0]=0;
                    pq.push(_mp(0, _mp(v,0)));
                }
            }else if(ar[v]==1){
                if (mini(dis[v][t], dis[u][t] + j.se)){
                    pq.push(_mp(dis[v][t], _mp(v, t)));
                }
            }else{
                if (mini(dis[v][t], dis[u][t] + j.se)){
                    pq.push(_mp(dis[v][t], _mp(v, t)));
                }
                //arr[v]=2 ->
                if (t + 1 <= k and mini(dis[v][t+1], (dis[u][t] + j.se)/2.0)){
                    pq.push(_mp(dis[v][t+1], _mp(v, t+1)));
                }
            }
        }
    }
    ld ans=-1;
    FOR(i,0,k){
        if (dis[h][i]!=-1){
//            cout << h << ' ' << i << ' ' << dis[h][i] << nl;
            mini(ans, dis[h][i]);
        }
    }
//    cout << fixed << setprecision(6) << "ans: " << ans << nl;
    return ans;
}
};

ld solve(int N, int M, int K, int H,
    vector<int> x, vector<int> y,
    vector<int> c, vector<int> arr) {

    n = N, m = M, k = K, h = H;

    FOR(i, 0, n - 1) ar[i] = arr[i];

    FOR(i, 0, n - 1) g[i].clear();

    for(int i = 0; i < m; ++i) {
        e[i] = edge(x[i], y[i], c[i]);
        g[x[i]].emplace_back(y[i], c[i]);
        g[y[i]].emplace_back(x[i], c[i]);
    }

    if (k <= 30) {
        return SUB1::sol();
    }

    return 0;
}


/*     Let the river flows naturally     */

• 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: 0 / 3