Submission #854841

#	Time	Username	Problem	Language	Result	Execution time	Memory
854841		wibulord	Commuter Pass (JOI18_commuter_pass)	C++14	31 / 100	396 ms	21228 KiB

commuter_pass

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl '\n'
#define ll long long
#define ull unsigned long long
#define db long double
#define fi first
#define se second
#define pb emplace_back
 
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pli pair<ll, int>
#define pdd pair<db, db>
#define iii pair<int, pair<int, int> >
 
#define ms(s, n) memset(s, n, sizeof(s))
#define all(a) a.begin(), a.end()
#define uni(a) (sort(all(a)), a.resize(unique(all(a))-a.begin()))
#define sz(a) (ll)((a).size())
 
#define bit(x) bitset<10>((x))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (1 &((x) >> (i)))
#define clz(x) __builtin_clz((x))
#define ctz(x) __builtin_ctz((x))
#define popc(x) __builtin_popcount((x))
#define clzll(x) __builtin_clzll((x))
#define ctzll(x) __builtin_ctzll((x))
#define popcll(x) __builtin_popcountll((x))
 
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define F0R(i, b) for (int i = 0, _b = (b); i < _b; ++i)
#define FORd(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define F0Rd(i, b) for (int i = (b)-1; i >= 0; i--)
#define rep(i, a) for (auto i : a)
 
using namespace std;
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
 
void print(int x) {cerr << x;}
void print(long long x) {cerr << x;}
void print(long double x) {cerr << x;}
void print(double x) {cerr << x;}
void print(unsigned long long x) {cerr << x;}
void print(char x) {cerr << x;}
void print(bool x) {cerr << (x ? "True" : "False");}
void print(string x) {cerr << x;}
 
template <typename T,typename H>
void print(pair<T,H> a) {cerr << "("; print(a.fi); cerr << ','; print(a.se); cerr << ')';}
template <typename T>
void print(T vec) {int cnt=0; cerr << "{"; rep(x,vec) cerr << (cnt++?",":""), print(x); cerr << '}';}
 
void show() {}
template <typename Head, typename ...Tail>
void show(Head H, Tail ...T){
    print(H);
    if (sizeof...(T)) cerr << ", ";
    show(T...);
}
#define debug(X...) cerr << "LINE "  << __LINE__ << " - " <<  "[" << #X << "] = [", show(X), cerr << "]\n"
 
template<typename T1,typename T2> bool ckmax(T1 &x,const T2 &y){if(x<y){x=y; return 1;} return 0;}
template<typename T1,typename T2> bool ckmin(T1 &x,const T2 &y){if(y<x){x=y; return 1;} return 0;}
 
inline int gcd(int x,int y){while(y){int tmp=y;y=x%y;x=tmp;} return (x);}
inline int lcm(int x,int y){return (int)(x*y)/gcd(x,y);}
 
void read(){}
template <typename Head, typename ...Tail>
void read(Head &H, Tail &...T)
{
    int sign = 0;
    char c;
    for (c = getchar(); !isdigit(c); c = getchar())
        if (c == '-') sign = 1;
    H = c - '0';
    for (c = getchar(); isdigit(c); c = getchar())
        H = H * 10 + c - '0';
    if (sign) H = -H;
    read(T...);
}
 
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r){return l + rd()% (r-l+1);}
 
const int MOD = 1000000007;
const int mod = 998244353;
const int oo = 1061109567;
const long long INF = 4557430888798830399;
const double PI = acos(-1);
const int N = 1e5 + 1, M = 1e2 + 5;
 
/*
     /\_/\
    (= ._.)
    / >?  \>$
*/
int n, m, s, t, u, v;
ll du[N], dv[N], ds[N], dp[2][N], ans;
bool Free[N];
vii adj[N];
 
void dijkstra1(int src, ll d[]){
   memset(Free, 0, (n+1)*sizeof(bool));
   priority_queue<pli, vector<pli>, greater<pli>> q; q.push({0, src});
   while(sz(q)){
      int u = q.top().se;
      ll c = q.top().fi;
      q.pop();
      if(!Free[u]){
         Free[u] = 1;
         d[u] = c;
         for(auto [v, w] : adj[u]) q.push({w + c, v});
      }
   }
}
 
void dijkstra2(int src, int en){
   memset(Free, 0, (n+1)*sizeof(bool));
   memset(dp[0], 0x3f, (n+1)*sizeof(ll));
   memset(dp[1], 0x3f, (n+1)*sizeof(ll));
   priority_queue<pair<ll, pii>, vector<pair<ll, pii>>, greater<pair<ll, pii>>> q;
   q.push({0, {src, 0}});
 
   while(sz(q)){
      int u = q.top().se.fi;
      int p = q.top().se.se;
      ll c = q.top().fi;
      q.pop();
 
      if(!Free[u]){
         Free[u] = 1;
         ds[u] = c;
         ckmin(dp[0][u], min(du[u], dp[0][p]));
         ckmin(dp[1][u], min(dv[u], dp[1][p]));
         for(auto [v, w] : adj[u]) q.push({c + w, {v, u}});
      }
      else if(ds[u] == c){
         if(min(du[u], dp[0][p]) + min(dv[u], dp[1][p]) <= dp[0][u] + dp[1][u]){
            ckmin(dp[0][u], min(du[u], dp[0][p]));
            ckmin(dp[1][u], min(dv[u], dp[1][p]));
         }
      }
   }
   ckmin(ans, dp[0][en] + dp[1][en]);
}
 
void sol(){
   cin >> n >> m >> s >> t >> u >> v;
   F0R(i, m){
      int x, y, z; cin >> x >> y >> z;
      adj[x].pb(y, z); adj[y].pb(x, z);
   }
   dijkstra1(u, du); dijkstra1(v, dv);
 
   ans = du[v];
   dijkstra2(s, t); dijkstra2(t, s);
   cout << ans << endl;
}
 
signed main(){
    #define TASK "nhap"
    if(fopen(TASK".inp", "r")){
        freopen(TASK".inp", "r", stdin);
//        freopen(TASK".out", "w", stdout);
    }
    fast; int t = 1;
//    cin >> t;
    while(t--) sol();
    cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << " ms\n";
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dijkstra1(int, long long int*)':
commuter_pass.cpp:127:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  127 |          for(auto [v, w] : adj[u]) q.push({w + c, v});
      |                   ^
commuter_pass.cpp: In function 'void dijkstra2(int, int)':
commuter_pass.cpp:150:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  150 |          for(auto [v, w] : adj[u]) q.push({c + w, {v, u}});
      |                   ^
commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:178:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  178 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45