Submission #1133701

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133701		tfgs	Construction Project 2 (JOI24_ho_t2)	C++17	100 / 100	178 ms	24884 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
#pragma GCC target("avx2")

#define int int64_t
const int inf=1e18;

#ifdef LOCAL
#include "algo/debug.h"
#else
template <typename... Args>
void dummy(Args&&... args){}
#define ps dummy
#endif

#define f first
#define s second
template<class T> using V = vector<T>; 
using vi = V<int>;
using vb = V<bool>;
using vs = V<string>;

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x) 
#define len(x) (int)((x).size())
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define ai2 array<int,2>
#define ai3 array<int,3>
#define ai4 array<int,4>
#define ai5 array<int,5>
template<class T> int lwb(const V<T>& a, const T& b) { return lb(all(a),b)-begin(a); }
template<class T> int upb(const V<T>& a, const T& b) { return ub(all(a),b)-begin(a); }
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a=b, true : false; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a=b, true : false; }
#define pct __builtin_popcountll
#define ctz __builtin_ctzll
#define clz __builtin_clzll
constexpr int p2(int x) { return (int)1 << x; }
constexpr int bits(int x) { return x == 0 ? 0 : 63-clz(x); } // floor(log2(x)) 
template<class T>void UNIQUE(V<T>& v) { sort(all(v)); v.erase(unique(all(v)),end(v)); }
template<class T,class U>void erase(T& t, const U& u) { auto it = t.find(u); assert(it != end(t)); t.erase(it); }
template<class F> struct y_combinator_result {
    F f;
    template<class T> explicit y_combinator_result(T &&f): f(std::forward<T>(f)) {}
    template<class ...Args> decltype(auto) operator()(Args &&...args) { return f(std::ref(*this), std::forward<Args>(args)...); }
};
template<class Fun> decltype(auto) yy(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); }
template<class T> using pqg = priority_queue<T,vector<T>,greater<T>>;

void solve() {
    int n, m; cin >> n >> m;
    int s, t, L, K; cin >> s >> t >> L >> K; s--; t--;
    V<V<ai2>> g(n);
    for (int i = 0; i < m; i++) {
        int u, v, w; cin >> u >> v >> w; u--; v--;
        g[u].pb({ v, w }); g[v].pb({ u, w });
    }
    auto dij = [&](int s) {
        vi d(n, inf);
        d[s] = 0;
        pqg<ai2> q;
        q.push({ 0, s });
        vb processed(n);
        while (len(q)) {
            auto [e, u] = q.top(); q.pop();
            if (processed[u]) continue;
            processed[u] = true;
            for (auto [v, w] : g[u]) if (ckmin(d[v], e + w)) {
                q.push({ d[v], v });
            }
        }
        return d;
    };
    vector d = { dij(s), dij(t) };
    if (d[0][t] <= K) {
        cout << n * (n - 1) / 2 << '\n';
        return;
    }
    K -= L;
    auto p = d[0], q = d[1];
    sort(all(p));
    sort(all(q));
    int ans = 0;
    int j = 0;
    for (int i = len(p) - 1; i >= 0; i--) {
        while (j < len(q) && p[i] + q[j] <= K) {
            j++;
        }
        ans += j;
    }
    cout << ans << '\n';
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}

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