Submission #813122

#	Time	Username	Problem	Language	Result	Execution time	Memory
813122		trangtranha28	Robot (JOI21_ho_t4)	C++14	100 / 100	1068 ms	80904 KiB

Main

#include <bits/stdc++.h>
#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define fore(x, v) for(auto &x : v)
#define fi first
#define se second
using namespace std; 
 
const long long INF = 1e15;
const int N = 1e5+5;
const int M = 2e5+5;
 
int n, m;
map <int, vector <pair <int, int> > > graph[N];
long long dp[N];
map<int, long long> dp2[N], sum[N];
 
int main() {
  cin >> n >> m;

  foru(i, 1, m) {
    int u, v, c, p;
    cin >> u >> v >> c >> p;
    graph[u][c].emplace_back(v, p);
    graph[v][c].emplace_back(u, p);
    sum[u][c] += p;
    sum[v][c] += p;
  } 

  memset(dp, 0x3f, sizeof(dp));
  priority_queue <pair <long long, pair <int, int> > > pq;
  dp[1] = 0;
  pq.push({0, {1, 0}});

  while (!pq.empty()) {
    auto top = pq.top(); pq.pop();

    long long cost = top.fi;
    int u = top.se.fi, c = top.se.se;

    if (!c) {
      if (-cost != dp[u]) continue;
      fore(nc, graph[u]) fore(info, nc.se) {
        int v = info.fi, p = info.se;
        long long ncost;

        ncost = sum[u][nc.fi] - p - cost;
        if (ncost < dp[v]) {
          dp[v] = ncost;
          pq.push({-ncost, {v, 0}});
        }

        ncost = p - cost;
        if (ncost < dp[v]) {
          dp[v] = ncost;
          pq.push({-ncost, {v, 0}});
        }

        ncost = -cost;
        if ((dp2[v].find(nc.fi) == dp2[v].end()) || ncost < dp2[v][nc.fi]) {
          dp2[v][nc.fi] = ncost;
          pq.push({-ncost, {v, nc.fi}});
        }
      }
    } 
    else {
      if (-cost != dp2[u][c]) continue;
      long long ncost = sum[u][c] - cost;
      fore(info, graph[u][c]) {
        int v = info.fi, p = info.se;
        if (ncost - p < dp[v]) {
          dp[v] = ncost - p;
          pq.push({-ncost + p, {v, 0}});
        }
      }
    }
  }

  cout << (dp[n] < INF ? dp[n] : -1);
  return 0;
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42