Submission #1123369

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123369		Whisper	Robot (JOI21_ho_t4)	C++20	100 / 100	913 ms	81484 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, a) for (int i = 0; i < (a); ++i)
#define REPD(i, a) for (int i = (a) - 1; i >= 0; --i)

#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)


constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

/*
    Phu Trong from Nguyen Tat Thanh High School for gifted student
*/

template <class X, class Y>
    bool minimize(X &x, const Y &y){
        X eps = 1e-9;
        if (x > y + eps) {x = y; return 1;}
        return 0;
    }

template <class X, class Y>
    bool maximize(X &x, const Y &y){
        X eps = 1e-9;
        if (x + eps < y) {x = y; return 1;}
        return 0;
    }
#define MAX_NODE                        100005
#define MAX_EDGE                        200005

int numNode, numEdge;

map<int, vector<pair<int, int>>> G[MAX_NODE];
map<int, int> same_color_sum[MAX_NODE];

int dp[MAX_NODE];
map<int, int> last_dp[MAX_NODE];

void process(void){
    cin >> numNode >> numEdge;
    for (int i = 1; i <= numEdge; ++i){
        int u, v, color, cost; cin >> u >> v >> color >> cost;
        G[u][color].emplace_back(v, cost);
        G[v][color].emplace_back(u, cost);

        same_color_sum[u][color] += cost;
        same_color_sum[v][color] += cost;
    }

    memset(dp, 0x3f, sizeof dp);
    #define T               tuple<int, int, int>
    priority_queue<T, vector<T>, greater<T>> q;

    q.emplace((dp[1] = 0), 1, 0);

    while(q.size()){
        int du, u, last_color;
        tie(du, u, last_color) = q.top(); q.pop();

        if(last_color == 0){
            if(du > dp[u]) continue;

            for (auto&c : G[u]){
                int w = same_color_sum[u][c.first];
                for (pair<int, int>&x : c.second){
                    int v = x.first, cost = x.second;

                    //change this edge
                    if(minimize(dp[v], du + cost)){
                        q.emplace(dp[v], v, 0);
                    }

                    //change all neighbour
                    if(minimize(dp[v], du + w - cost)){
                        q.emplace(dp[v], v, 0);
                    }

                    if (!last_dp[v].count(c.first) || last_dp[v][c.first] > du){
                        last_dp[v][c.first] = du;
                        q.emplace(last_dp[v][c.first], v, c.first);
                    }
                }
            }
        }
        else{
            int now = last_dp[u][last_color];
            int w = same_color_sum[u][last_color];

            if(du != now) continue; //not optimial way

            for (pair<int, int>&x : G[u][last_color]){
                int cost = x.second, v = x.first;
                if(minimize(dp[v], now + w - cost)){
                    q.emplace(dp[v], v, 0);
                }
            }
        }
    }
    cout << (dp[numNode] >= LINF ? -1 : dp[numNode]);
}
signed main(){
    #define name "Whisper"
    cin.tie(nullptr) -> sync_with_stdio(false);
    // freopen(name".inp", "r", stdin);
    // freopen(name".out", "w", stdout);
    process();
    return (0 ^ 0);
}

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