Submission #212352

#	Time	Username	Problem	Language	Result	Execution time	Memory
212352		b00n0rp	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	860 ms	3572 KiB

ho_t4

#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <vector>
using namespace std;

typedef long long ll;
#define int ll
#define pb push_back
#define REP(i,n) for (int i = 0; i < n; i++)
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define remin(a,b) a = min(a,b)
typedef map<int,int> mii;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;
#define F first
#define S second
#define sfl2(x,y) scanf("%lld%lld",&x,&y);
#define pfi(x) printf("%d\n",x);
#define pfl(x) printf("%lld\n",x);

const int INF=1e10;

int n,m;
vector<pair<pii,pii> > edges;
vi adj[205];
int dist[205][205];
int p1[205],p2[205];
int lol[205];

set<int> s;

int dijkstra(){
	REP(i,205) lol[i] = INF;
	lol[1] = 0;
	priority_queue<pii,vpii,greater<pii> > pq;
	pq.push({0,1});
	while(pq.size()){
		int u = pq.top().S;
		pq.pop();
		for(auto e:adj[u]){
			int v = edges[e].F.S,w = edges[e].S.F;
			if(lol[v] > lol[u]+w){
				lol[v] = lol[u]+w;
				pq.push({lol[v],v});
				p1[v] = e;
			}
		}
	}
	int res = lol[n];
	REP(i,205) lol[i] = INF;
	lol[n] = 0;
	pq.push({0,n});
	while(pq.size()){
		int u = pq.top().S;
		pq.pop();
		for(auto e:adj[u]){
			int v = edges[e].F.S,w = edges[e].S.F;
			if(lol[v] > lol[u]+w){
				lol[v] = lol[u]+w;
				pq.push({lol[v],v});
				p2[v] = e;
			}
		}
	}
	return res+lol[1];
}
 
signed main(){
	sfl2(n,m)
	REP(i,205){
		p1[i] = -1;
		p2[i] = -1;
		REP(j,205){
			dist[i][j] = INF;
		}
		dist[i][i] = 0;
	}
	REP(i,m){
		int u,v,c,d;
		sfl2(u,v)
		sfl2(c,d)
		edges.pb({{u,v},{c,d}});
		adj[u].pb(i);
		adj[v].pb(i);
		remin(dist[u][v],c);
	}
	
	FOR(k,1,n+1){
		FOR(i,1,n+1){
			FOR(j,1,n+1){
				remin(dist[i][j],dist[i][k]+dist[k][j]); 
			}
		}
	}
	int ans = dist[1][n]+dist[n][1];
	dijkstra();
	// trace(dijkstra(),ans);
	FOR(i,1,n+1){
		// trace(i,p1[i],p2[i]);
		if(p1[i] != -1) s.insert(p1[i]);
		if(p2[i] != -1) s.insert(p2[i]);
	}
	REP(i,m){
		if(s.find(i) == s.end()){
			// trace(i,edges[i].S.S,dist[1][edges[i].F.S],dist[edges[i].F.F][n],edges[i].S.F);
			remin(ans,edges[i].S.S+min(dist[1][n],dist[1][edges[i].F.S]+dist[edges[i].F.F][n]+edges[i].S.F)+min(dist[n][1],dist[n][edges[i].F.S]+dist[edges[i].F.F][1]+edges[i].S.F));
		}
		else{
			swap(edges[i].F.F,edges[i].F.S);
			// trace(i,dijkstra(),edges[i].S.S);
			remin(ans,dijkstra()+edges[i].S.S);
			swap(edges[i].F.F,edges[i].F.S);
		}
	}
	if(ans > 1LL*(1e12)) pfi(-1)
	else pfl(ans)
}

Compilation message (stderr)

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:22:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define sfl2(x,y) scanf("%lld%lld",&x,&y);
                   ~~~~~^~~~~~~~~~~~~~~~~~
ho_t4.cpp:74:2: note: in expansion of macro 'sfl2'
  sfl2(n,m)
  ^~~~
ho_t4.cpp:22:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define sfl2(x,y) scanf("%lld%lld",&x,&y);
                   ~~~~~^~~~~~~~~~~~~~~~~~
ho_t4.cpp:85:3: note: in expansion of macro 'sfl2'
   sfl2(u,v)
   ^~~~
ho_t4.cpp:22:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define sfl2(x,y) scanf("%lld%lld",&x,&y);
                   ~~~~~^~~~~~~~~~~~~~~~~~
ho_t4.cpp:86:3: note: in expansion of macro 'sfl2'
   sfl2(c,d)
   ^~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63