Submission #759257

#	Time	Username	Problem	Language	Result	Execution time	Memory
759257		GrindMachine	Robot (JOI21_ho_t4)	C++17	100 / 100	1638 ms	156540 KiB

Main

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://usaco.guide/problems/joi-2021robot/solution

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<array<ll,4>> adj1[N];
map<ll,vector<array<ll,3>>> adj2[N];
map<ll,ll> adj_sum[N];

void solve(int test_case)
{
    ll n,m; cin >> n >> m;
    vector<array<ll,4>> edges(m+5);

    rep1(i,m){
        ll u,v,c,w; cin >> u >> v >> c >> w;
        edges[i] = {u,v,c,w};
        adj1[u].pb({v,c,w,i});
        adj1[v].pb({u,c,w,i});
        adj2[u][c].pb({v,w,i});
        adj2[v][c].pb({u,w,i});
        adj_sum[u][c] += w;
        adj_sum[v][c] += w;
    }

    priority_queue<array<ll,3>,vector<array<ll,3>>,greater<array<ll,3>>> pq;
    pq.push({0,1,-1});
    set<pll> st;

    while(!pq.empty()){
        auto [cost,u,prevc] = pq.top();
        pq.pop();

        pll px = {u,prevc};
        if(st.count(px)) conts;
        st.insert(px);

        if(u == n and prevc == -1){
            cout << cost << endl;
            return;
        }

        if(prevc == -1){
            for(auto [v,c,w,id] : adj1[u]){
                // recolor edge and put ?

                // next edge is ?
                pq.push({cost+w,v,-1});

                // next edge is not '?' and has col c
                pq.push({cost,v,c});

                // retain color
                ll add = adj_sum[u][c];
                add -= w;
                pq.push({cost+add,v,-1});
            }
        }
        else{
            ll c = prevc;
            for(auto [v,w,id] : adj2[u][c]){
                // recolor all adj guys
                ll add = adj_sum[u][c];
                add -= w;
                pq.push({cost+add,v,-1});
            }
        }
    }

    cout << -1 << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42