Submission #958973

#	Time	Username	Problem	Language	Result	Execution time	Memory
958973		nguyentunglam	Cyberland (APIO23_cyberland)	C++17	0 / 100	193 ms	59040 KiB

cyberland

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

const int N = 1e5 + 10;

int a[N];

double d[31][N];

bool vis[31][N];

bool _vis[N];

vector<int> start;

vector<pair<int, int> > adj[N];

int n, h, k;

#define ii pair<double, int>

priority_queue<ii, vector<ii>, greater<ii> > q[31];

void dfs(int u) {
  _vis[u] = 1;
  if (a[u] == 0 || u == 0) q[0].push({d[0][u] = 0, u});
  for(auto &[v, w] : adj[u]) if (!_vis[v] && v != h) dfs(v);
}

double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int> y, std::vector<int> c, std::vector<int> arr) {
  n = N;
  h = H;
  k = K;
  for(int i = 0; i < n; i++) adj[i].clear(), _vis[i] = 0;
  for(int i = 0; i < x.size(); i++) {
    adj[x[i]].emplace_back(y[i], c[i]);
    adj[y[i]].emplace_back(x[i], c[i]);
  }
  for(int j = 0; j <= k; j++) for(int i = 0; i < n; i++) d[j][i] = 1e16, vis[j][i] = 0;
  for(int i = 0; i < n; i++) a[i] = arr[i];
  dfs(0);
  for(int j = 0; j <= k; j++) {
    while (!q[j].empty()) {
      auto [cost, u] = q[j].top(); q[j].pop();
      if (vis[j][u]) continue;
      if (u == h) continue;
      vis[j][u] = 1;
      for(auto &[v, w] : adj[u]) {
        if (d[j + 1][v] > d[j][u] / 2 + w) q[j + 1].push({d[j + 1][v] = d[j][u] / 2 + w, v});
        if (d[j][v] > d[j][u] + w) q[j].push({d[j][v] = d[j][u] + w, v});
      }
    }
  }

  double ans = 1e18;
  for(int j = 0; j <= k; j++) ans = min(ans, d[j][h]);

  if (ans > 1e16) ans = -1;

  return ans;
}

#ifdef ngu
int main() {
  freopen ("task.inp", "r", stdin);
  freopen ("task.out", "w", stdout);
  int T;
  assert(1 == scanf("%d", &T));
  while (T--){
    int N,M,K,H;
    assert(4 == scanf("%d %d %d\n%d", &N, &M, &K, &H));
    std::vector<int> x(M);
    std::vector<int> y(M);
    std::vector<int> c(M);
    std::vector<int> arr(N);
    for (int i=0;i<N;i++)
      assert(1 == scanf("%d", &arr[i]));
    for (int i=0;i<M;i++)
      assert(3 == scanf("%d %d %d", &x[i], &y[i], &c[i]));
    printf("%.12lf\n", solve(N, M, K, H, x, y, c, arr));
  }
}
#endif // ngu

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:37:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |   for(int i = 0; i < x.size(); i++) {
      |                  ~~^~~~~~~~~~

• Subtask 1: 0 / 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