Submission #1101201

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101201		KasymK	Commuter Pass (JOI18_commuter_pass)	C++17	0 / 100	180 ms	21236 KiB

commuter_pass

#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N = 1e5+5;
const ll INF = 1e18;
vector<pii> adj[N];
ll dis[N], diss[N];
int n;

void dij(int s){
	for(int i = 1; i <= n; ++i)
		dis[i] = INF;
	priority_queue<pli, vector<pli>, greater<pli>> pq;
	pq.push({0, s});
	dis[s] = 0;
	while(!pq.empty()){
		int x = pq.top().ss;
		ll val = pq.top().ff;
		pq.pop();
		if(dis[x] != val)
			continue;
		tr(it, adj[x]){
			int a = it->ff, w = it->ss;
			if(umin(dis[a], dis[x]+w))
				pq.push({dis[a], a});
		}
	}
}

int main(){
	int m, s, t, u, v;
	scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
	using node = tuple<int, int, int>;
	vector<node> A;
	for(int i = 1; i <= m; ++i){
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		adj[a].pb({b, c});
		adj[b].pb({a, c});
		A.pb({a, b, c});
	}
	ll possible = -1;
	dij(u);
	possible = dis[v];
	dij(s);
	for(int i = 1; i <= n; ++i)
		diss[i] = dis[i];
	dij(t);
	for(auto &i : A){
		int a, b, c;
		tie(a, b, c) = i;
		if(diss[a]+dis[b]+c==diss[t]){
			adj[a].pb({b, 0});
			adj[b].pb({a, 0});
		}
	}
	dij(u);
	assert(~possible);
	printf("%lld\n", min(possible, dis[v]));
	return 0;
}

Compilation message (stderr)

commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:43:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |  scanf("%d%d%d%d%d%d", &n, &m, &s, &t, &u, &v);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:48:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |   scanf("%d%d%d", &a, &b, &c);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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