Submission #986702

#	Time	Username	Problem	Language	Result	Execution time	Memory
986702		CSQ31	Cyberland (APIO23_cyberland)	C++17	5 / 100	130 ms	20060 KiB

cyberland

#include "cyberland.h"
#include<bits/stdc++.h>
using namespace std;
 
typedef long double ld;
ld dist[64][111111];
ld pw[64];
struct node{
    int v,k;
    ld dist = 0;
    node(int _v,int _k,ld _dist = 0){
        v = _v;
        k = _k;
        dist = _dist;
    }
};
 
struct comp
{
    bool operator() (node const &a, node const &b) { return a.dist - b.dist > 1e-10; }
};
vector<pair<int,int>>adj[111111];
double solve(int n, int m,int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr){
    priority_queue<node,vector<node>,comp>pq;
    for(int j=0;j<n;j++){
        adj[j].clear();
        for(int i=0;i<=64;i++){
            dist[i][j] = 1e15;
        }
    }
    pw[0] = 1;
    for(int i=1;i<=64;i++)pw[i] = pw[i-1]*2;
    for(int i=0;i<m;i++){
        adj[x[i]].push_back({y[i],c[i]});
        adj[y[i]].push_back({x[i],c[i]});
    }
    K = min(K,64);
    dist[0][H] = 0;
    pq.push(node(H,0));
    while(!pq.empty()){
        node tmp = pq.top();
        int v = tmp.v;
        int k = tmp.k;
        //cout<<v<<" "<<k<<" "<<tmp.dist<<" "<<dist[k][v]<<'\n';
        pq.pop();
        if(abs(tmp.dist - dist[k][v]) > 1e-10)continue;
        if(arr[v] == 0)continue;
 
        for(pair<int,int>x : adj[v]){
            int u = x.first;
          if(u == H)continue;
            ld w = x.second/pw[k];
            if(dist[k][u] - dist[k][v] - w > 1e-10){
                dist[k][u] = dist[k][v] + w;
                pq.push(node(u,k,dist[k][u]));
            }
            if(arr[u] == 2 && k+1 <= K){
                if(dist[k+1][u] - dist[k][v] - w > 1e-10){
                    dist[k+1][u] = dist[k][v] + w;
                    pq.push(node(u,k+1,dist[k+1][u]));
                }
 
            }
        }
    }
    ld ans = 1e18;
    for(int i=0;i<=K;i++)ans = min(ans,dist[i][0]);
    queue<int>q;
    vector<int>vis(n,0);
    q.push(0);
    vis[0] = 1;
    while(!q.empty()){
        int v = q.front();
        q.pop();
        if(arr[v] == 0){
            for(int i=0;i<=K;i++)ans = min(ans,dist[i][v]);   
        }
      if(v==H)continue;
        for(pair<int,int>x:adj[v]){
            int u = x.first;
            if(!vis[u]){
                q.push(u);
                vis[u] = 1;
            }
        }
    }
    if(!vis[H])return -1;
    return ans;
}

Compilation message (stderr)

cyberland.cpp: In function 'double solve(int, int, int, int, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
cyberland.cpp:28:24: warning: iteration 64 invokes undefined behavior [-Waggressive-loop-optimizations]
   28 |             dist[i][j] = 1e15;
      |             ~~~~~~~~~~~^~~~~~
cyberland.cpp:27:22: note: within this loop
   27 |         for(int i=0;i<=64;i++){
      |                     ~^~~~
cyberland.cpp:32:33: warning: iteration 63 invokes undefined behavior [-Waggressive-loop-optimizations]
   32 |     for(int i=1;i<=64;i++)pw[i] = pw[i-1]*2;
      |                           ~~~~~~^~~~~~~~~~~
cyberland.cpp:32:18: note: within this loop
   32 |     for(int i=1;i<=64;i++)pw[i] = pw[i-1]*2;
      |                 ~^~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3