Submission #1087553

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087553		HienTD	Construction Project 2 (JOI24_ho_t2)	C++14	0 / 100	5 ms	11356 KiB

Main

#include <bits/stdc++.h>
using namespace std;

//#define USACO

#define             fi  first
#define             se  second
#define           TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define         ALL(v)  (v).begin(), (v).end()
#define         BIT(i)  (1LL << (i))
#define     MASK(x, i)  (((x) >> (i)) & 1)
#define      REP(i, v)  for( __typeof((v).begin()) i = (v).begin(); i != (v).end(); ++ i)
#define   FOR(i, a, b)  for(int i = (a), _b = (b); i <= _b; ++ i)
#define  FORD(i, b, a)  for(int i = (b), _a = (a); i >= _a; -- i)

const string NAME = "BAITAP";

const string name = "";

const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const int mod = 998244353;

const int mxN = 2e5 + 5;

int N, M, S, T, L;
long long K;
vector<pair<int, int>> edge[mxN];
vector<vector<long long>> d(3, vector<long long> (mxN));

void init(void){
    cin >> N >> M;
    cin >> S >> T >> L >> K;
    FOR(i, 1, M){
        int u, v, w;
        cin >> u >> v >> w;
        edge[u].push_back(make_pair(v, w));
        edge[v].push_back(make_pair(u, w));
    }
}

void dijkstra(int s, int t){
    FOR(i, 1, N) d[t][i] = INF;
    d[t][s] = 0;
    priority_queue<pair<long long, int>, vector<pair<long long, int>> , greater<pair<long long, int>>> pq;
    pq.push(make_pair(0, s));
    while(pq.empty() == false){
        pair<long long, int> cur = pq.top();
        pq.pop();
        if(d[t][cur.se] != cur.fi) continue;
        for(pair<int, int> v : edge[cur.se]){
            if(d[t][v.fi] > v.se + d[t][cur.se]) pq.push(make_pair(d[t][v.fi] = v.se + d[t][cur.se], v.fi));
        }
    }
}

void process(void){
    dijkstra(S, 0);
    dijkstra(T, 1);
    if(d[0][T] <= K){
        cout << 1LL * N * (N - 1) / 2;
        return;
    }
}

signed main(void){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    #ifdef LOCAL
        freopen((NAME + ".INP").c_str(), "r", stdin);
        freopen((NAME + ".OUT").c_str(), "w", stdout);
    #elif defined(USACO)
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    #endif

    init();
    process();
    cerr << "\nTime elapsed: " << TIME << "s.\n";
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 16
• Subtask 3: 0 / 29
• Subtask 4: 0 / 47