oj.uz

Submission #335767

# Submission time Handle Problem Language Result Execution time Memory
335767 2020-12-13T23:16:51 Z VROOM_VARUN Cities (BOI16_cities) C++14
100 / 100
 4043 ms 77048 KB 
/*
ID: varunra2
LANG: C++
TASK: cities
*/

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

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define int long long

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e15
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

int n, k, m;
VVI dp;
VVI dp1;
vector<VII> adj;
VI which;
VVI pws;
vector<bool> vis;

// we can get submasks by doing base 3...

void init() {
  dp.resize(1 << k);
  trav(x, dp) x.assign(n, INF);
  adj.resize(n);
  which.assign(n, -1);
  pws.resize(1 << k);
}

void dijk(int type) {
  // if we want to come from a neighbor
  priority_queue<PII, VII, greater<PII>> pq;

  for (int i = 0; i < n; i++) {
    pq.push(MP(dp[type][i], i));
  }

  while (!pq.empty()) {
    auto xx = pq.top();
    pq.pop();
    int u = xx.y;
    if (vis[u]) continue;
    vis[u] = true;
    for (auto& x : adj[u]) {
      if (vis[x.x]) continue;
      if (dp[type][x.x] > xx.x + x.y) {
        dp[type][x.x] = xx.x + x.y;
        pq.push(MP(dp[type][x.x], x.x));
      }
    }
  }
}

void dfs(int ind, int type) {
  if (vis[ind]) return;
  vis[ind] = true;
  for (auto& x : pws[type]) {
    dp[type][ind] = min(dp[type][ind], dp[x][ind] + dp[type ^ x][ind]);
  }
  for (auto& x : adj[ind]) {
    dfs(x.x, type);
  }
}

void gen() {
  int pw = 1;
  for (int i = 0; i < k; i++) pw *= 3;
  for (int i = 0; i < pw; i++) {
    VI vals(k, 0);
    int ind = 0;
    int cop = i;
    while (cop) {
      vals[ind++] = cop % 3;
      cop /= 3;
    }
    int val1 = 0;
    int val2 = 0;
    for (int i = 0; i < k; i++) {
      if (vals[i] >= 1) val1 |= (1 << i);
      if (vals[i] == 2) val2 |= (1 << i);
    }
    pws[val1].PB(val2);
  }
}

void process(int type) {
  vis.assign(n, false);
  dfs(0, type);
  vis.assign(n, false);
  dijk(type);
}

int32_t main() {
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n >> k >> m;

  init();

  for (int i = 0; i < k; i++) {
    int u;
    cin >> u;
    u--;
    which[u] = i;
  }

  for (int i = 0; i < m; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    u--, v--;
    adj[u].PB(MP(v, w));
    adj[v].PB(MP(u, w));
  }

  for (int i = 0; i < n; i++) {
    dp[0][i] = 0;
  }

  for (int i = 0; i < n; i++) {
    if (~which[i]) dp[1 << which[i]][i] = 0;
  }

  dp1 = dp;

  gen();

  for (int i = 1; i < (1 << k); i++) process(i);

  cout << *min_element(all(dp[(1 << k) - 1])) << '\n';


  return 0;
}

Subtask #1
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 392 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct

Subtask #2
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 943 ms 34840 KB Output is correct
2 Correct 890 ms 32540 KB Output is correct
3 Correct 586 ms 26904 KB Output is correct
4 Correct 95 ms 9652 KB Output is correct
5 Correct 502 ms 28744 KB Output is correct
6 Correct 80 ms 13036 KB Output is correct
7 Correct 4 ms 748 KB Output is correct
8 Correct 3 ms 620 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 748 KB Output is correct
2 Correct 7 ms 876 KB Output is correct
3 Correct 5 ms 748 KB Output is correct
4 Correct 6 ms 748 KB Output is correct

Subtask #4
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 1927 ms 47392 KB Output is correct
2 Correct 1811 ms 49172 KB Output is correct
3 Correct 1344 ms 41780 KB Output is correct
4 Correct 1022 ms 34172 KB Output is correct
5 Correct 252 ms 17588 KB Output is correct
6 Correct 126 ms 15416 KB Output is correct

Subtask #5
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 3998 ms 72532 KB Output is correct
2 Correct 4043 ms 77048 KB Output is correct
3 Correct 3782 ms 74892 KB Output is correct
4 Correct 2853 ms 67104 KB Output is correct
5 Correct 2097 ms 46724 KB Output is correct
6 Correct 423 ms 20172 KB Output is correct
7 Correct 182 ms 15284 KB Output is correct