Submission #485264

#	Time	Username	Problem	Language	Result	Execution time	Memory
485264		xiaowuc1	주유소 (KOI16_gas)	C++17	100 / 100	799 ms	708 KiB

gas

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <vector>

using namespace std;

// BEGIN NO SAD
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
typedef vector<int> vi;
#define f first
#define s second
#define derr if(1) cerr
// END NO SAD

template<class Fun>
class y_combinator_result {
  Fun fun_;
public:
  template<class T>
  explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

  template<class ...Args>
  decltype(auto) operator()(Args &&...args) {
    return fun_(std::ref(*this), std::forward<Args>(args)...);
  }
};

template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
  return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<vector<ll>> matrix;

void solve() {
  int n, m;
  cin >> n >> m;
  vector<pii> gasprices(n);
  for(int i = 0; i < n; i++) {
    int x;
    cin >> x;
    gasprices[i] = {x, i};
  }
  sort(all(gasprices));
  vector<vector<pii>> edges(n);
  while(m--) {
    int a, b, w;
    cin >> a >> b >> w;
    a--; b--;
    edges[a].eb(b, w);
    edges[b].eb(a, w);
  }
  vector<ll> cost(n, 1e18);
  cost[0] = 0;
  while(sz(gasprices)) {
    auto [currp, src] = gasprices.back(); gasprices.pop_back();
    vector<int> dp(n, 2e9);
    dp[src] = 0;
    priority_queue<pii> q;
    q.emplace(-dp[src], src);
    while(sz(q)) {
      auto [w, v] = q.top(); q.pop();
      w *= -1;
      if(dp[v] != w) continue;
      for(auto [nv, gain]: edges[v]) {
        if(dp[v] + gain < dp[nv]) {
          dp[nv] = dp[v] + gain;
          q.emplace(-dp[nv], nv);
        }
      }
    }
    for(int i = 0; i < n; i++) {
      cost[i] = min(cost[i], cost[src] + dp[i] * (ll)currp);
    }
  }
  cout << cost[n-1] << "\n";
}

// what would chika do
// are there edge cases (N=1?)
// are array sizes proper (scaled by proper constant, for example 2* for koosaga tree)
// integer overflow?
// DS reset properly between test cases
// are you doing geometry in floating points
// are you not using modint when you should

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
}

• Subtask 1: 18 / 18
• Subtask 2: 15 / 15
• Subtask 3: 16 / 16
• Subtask 4: 24 / 24
• Subtask 5: 27 / 27