Submission #1087613

# Submission time Handle Problem Language Result Execution time Memory
1087613 2024-09-13T02:48:39 Z Whisper Aesthetic (NOI20_aesthetic) C++17
35 / 100
734 ms 51988 KB
#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                 300005
int numNode, numEdge;
vector<int> G[MAX];
struct Edge{
    int u, v, w;
    Edge(){}
    Edge(int _u, int _v, int _w): u(_u), v(_v), w(_w){}

    int other(int x){return (x ^ u ^ v);}
} edge[MAX];
int minDist[2][MAX];

void dijkstra(int s, int minDist[]){
    for (int i = 1; i <= numNode; ++i) minDist[i] = LINF;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
    q.emplace(0, s);
    minDist[s] = 0;
    while(q.size()){
        int du, u; tie(du, u) = q.top(); q.pop();
        if(du > minDist[u]) continue;

        for(int&i : G[u]) {
            int v = edge[i].other(u);
            if(minimize(minDist[v], minDist[u] + edge[i].w)){
                q.emplace(minDist[v], v);
            }
        }
    }
}

int low[MAX], num[MAX], timeDfs = 0;

int suffix[MAX];
bool contain[MAX];
vector<pair<int, int>> newG[MAX];
bool ok = 0;

int value = 0;
void tarjan(int u, int p){
    if(u == numNode) contain[u] = true;
    low[u] = num[u] = ++timeDfs;
    for (pair<int, int>&x : newG[u]){
        int v = x.first, i = x.second;
        if(v ^ p){
            if(num[v]) minimize(low[u], num[v]);
            else{
                tarjan(v, u);
                minimize(low[u], low[v]);
                contain[u] |= contain[v];

                if(num[v] == low[v]){
                    if(!contain[v]) continue;
                    if(minDist[0][u] + edge[i].w + minDist[1][v] != minDist[0][numNode]) continue;
                    if(minDist[0][u] + edge[i].w + minDist[1][v] + suffix[i] >= minDist[0][numNode] + value)
                        ok = 1;
                }
            }
        }
    }
}

void process(void){
    cin >> numNode >> numEdge;
    int max_weight = 0;
    for (int i = 1; i <= numEdge; ++i){
        cin >> edge[i].u >> edge[i].v >> edge[i].w;
        G[edge[i].u].emplace_back(i);
        G[edge[i].v].emplace_back(i);
        maximize(max_weight, edge[i].w);
    }

    dijkstra(1, minDist[0]);
    dijkstra(numNode, minDist[1]);

    for (int i = numEdge - 1; i >= 1; --i){
        maximize(suffix[i], suffix[i + 1]);
        maximize(suffix[i], edge[i + 1].w);
    }

    for (int i = 1; i <= numEdge; ++i){
        if(minDist[0][edge[i].u] > minDist[0][edge[i].v]) swap(edge[i].u, edge[i].v);
    }
    int l = 0, r = max_weight;
    int add = 0;

    auto check = [&](int val) -> bool{
        timeDfs = 0, ok = 0;
        value = val;
        for (int i = 1; i <= numNode; ++i) newG[i].clear(), contain[i] = num[i] = low[i] = 0;

        auto active = [&](int u, int v, int w, int x) -> bool{
            if(minDist[0][u] + minDist[1][v] + w < minDist[0][numNode] + x) return true;
            if(minDist[0][v] + minDist[1][u] + w < minDist[0][numNode] + x) return true;
            return false;
        };

        for (int u = 1; u <= numNode; ++u){
            for (int&i : G[u]){
                int v = edge[i].other(u);
                if(active(u, v, edge[i].w, val)) {
                    newG[u].emplace_back(v, i);
                }
            }
        }
        tarjan(1, 0);
        return (ok);
    };

    while(l <= r){
        int m = (l + r) >> 1;
        if(check(m)) l = m + 1, add = m;
        else r = m - 1;
    }

    cout << minDist[0][numNode] + add;
}
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);
}




Compilation message

Aesthetic.cpp: In lambda function:
Aesthetic.cpp:126:81: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  126 |         for (int i = 1; i <= numNode; ++i) newG[i].clear(), contain[i] = num[i] = low[i] = 0;
      |                                                                          ~~~~~~~^~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 6 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14524 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 7 ms 14428 KB Output is correct
8 Correct 5 ms 14424 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 6 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14524 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 7 ms 14428 KB Output is correct
8 Correct 5 ms 14424 KB Output is correct
9 Correct 8 ms 14668 KB Output is correct
10 Correct 7 ms 14684 KB Output is correct
11 Correct 7 ms 14604 KB Output is correct
12 Correct 10 ms 14828 KB Output is correct
13 Correct 6 ms 14836 KB Output is correct
14 Correct 7 ms 14684 KB Output is correct
15 Correct 6 ms 14684 KB Output is correct
16 Correct 7 ms 14684 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 565 ms 51076 KB Output is correct
2 Correct 639 ms 51244 KB Output is correct
3 Correct 671 ms 50772 KB Output is correct
4 Correct 602 ms 51028 KB Output is correct
5 Correct 641 ms 50936 KB Output is correct
6 Correct 671 ms 51804 KB Output is correct
7 Correct 617 ms 51540 KB Output is correct
8 Correct 620 ms 51792 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 734 ms 51988 KB Output is correct
2 Correct 602 ms 51280 KB Output is correct
3 Correct 609 ms 51328 KB Output is correct
4 Correct 594 ms 51544 KB Output is correct
5 Correct 733 ms 51148 KB Output is correct
6 Correct 566 ms 51216 KB Output is correct
7 Correct 602 ms 51220 KB Output is correct
8 Correct 569 ms 51540 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 213 ms 45152 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 213 ms 45152 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 6 ms 14428 KB Output is correct
2 Correct 5 ms 14428 KB Output is correct
3 Correct 5 ms 14428 KB Output is correct
4 Correct 5 ms 14428 KB Output is correct
5 Correct 5 ms 14524 KB Output is correct
6 Correct 5 ms 14428 KB Output is correct
7 Correct 7 ms 14428 KB Output is correct
8 Correct 5 ms 14424 KB Output is correct
9 Correct 8 ms 14668 KB Output is correct
10 Correct 7 ms 14684 KB Output is correct
11 Correct 7 ms 14604 KB Output is correct
12 Correct 10 ms 14828 KB Output is correct
13 Correct 6 ms 14836 KB Output is correct
14 Correct 7 ms 14684 KB Output is correct
15 Correct 6 ms 14684 KB Output is correct
16 Correct 7 ms 14684 KB Output is correct
17 Correct 565 ms 51076 KB Output is correct
18 Correct 639 ms 51244 KB Output is correct
19 Correct 671 ms 50772 KB Output is correct
20 Correct 602 ms 51028 KB Output is correct
21 Correct 641 ms 50936 KB Output is correct
22 Correct 671 ms 51804 KB Output is correct
23 Correct 617 ms 51540 KB Output is correct
24 Correct 620 ms 51792 KB Output is correct
25 Correct 734 ms 51988 KB Output is correct
26 Correct 602 ms 51280 KB Output is correct
27 Correct 609 ms 51328 KB Output is correct
28 Correct 594 ms 51544 KB Output is correct
29 Correct 733 ms 51148 KB Output is correct
30 Correct 566 ms 51216 KB Output is correct
31 Correct 602 ms 51220 KB Output is correct
32 Correct 569 ms 51540 KB Output is correct
33 Incorrect 213 ms 45152 KB Output isn't correct
34 Halted 0 ms 0 KB -