Submission #969404

#	Time	Username	Problem	Language	Result	Execution time	Memory
969404		blackslex	Cities (BOI16_cities)	C++17	100 / 100	2229 ms	54912 KiB

cities

#include<bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<ll, ll>;

int n, m, k, x, y;
ll z;

int main() {
    scanf("%d %d %d", &n, &k, &m);
    vector<int> c(k);
    vector<vector<pii>> v(n + 5, vector<pii>());
    for (auto &e: c) scanf("%d", &e);
    while (m--) scanf("%d %d %lld", &x, &y, &z), v[x].emplace_back(y, z), v[y].emplace_back(x, z);
    vector<vector<ll>> dp((1 << k) + 5, vector<ll>(n + 5, 1e18));
    for (int i = 0; i < k; i++) dp[1 << i][c[i]] = 0;
    for (int i = 1; i < (1 << k); i++) {
        for (int j = i; j; j = (j - 1) & i) {
            for (int r = 1; r <= n; r++) {
                dp[i][r] = min(dp[i][r], dp[j][r] + dp[i ^ j][r]);
            }
        }
        auto dijk = [&] (vector<ll> &curd) {
            priority_queue<pii, vector<pii>, greater<pii>> pq;
            for (int j = 1; j <= n; j++) pq.emplace(curd[j], j);
            while (!pq.empty()) {
                auto [nd, nn] = pq.top(); pq.pop();
                for (auto &[tn, td]: v[nn]) if (curd[tn] > curd[nn] + td) pq.emplace(curd[tn] = curd[nn] + td, tn);
            }
        };
        dijk(dp[i]);
    }
    printf("%lld", *min_element(dp[(1 << k) - 1].begin(), dp[(1 << k) - 1].end()));
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:11:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     scanf("%d %d %d", &n, &k, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:14:27: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     for (auto &e: c) scanf("%d", &e);
      |                      ~~~~~^~~~~~~~~~
cities.cpp:15:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     while (m--) scanf("%d %d %lld", &x, &y, &z), v[x].emplace_back(y, z), v[y].emplace_back(x, z);
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26