oj.uz

Submission #320427

# Submission time Handle Problem Language Result Execution time Memory
320427 2020-11-08T18:13:25 Z AmineWeslati Olympic Bus (JOI20_ho_t4) C++14
0 / 100
 42 ms 7508 KB 
//Never stop trying
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
#define int ll
typedef string str;
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 200 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}

#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}

struct edge{
	int u,v,w,ww;
};

int N,M;
vpi adj[202],adj2[202];
V<edge> vec;
map<pair<pi,int>,int> mp;

int d[202]; //dist(1,u)
int d2[202]; //dist(u,N)
int d3[202]; //dist(N,u)
int d4[202]; //dist(u,1);
int d5[50001]; //dist(1,N) without edge[i]
int d6[50001]; //dist(N,1) without edge[i]

void precompute(){
	fill(d,d+N+1,INF); d[1]=0;
	fill(d2,d2+N+1,INF); d2[N]=0;
	fill(d3,d3+N+1,INF); d3[N]=0;
	fill(d4,d4+N+1,INF); d4[1]=0;
	fill(d5,d5+M,INF);
	fill(d6,d6+M,INF);
	priority_queue<pi,vpi,greater<pi>> q;

	//d
	q.push({0,1});
	while(!q.empty()){
		int u=q.top().se,dd=q.top().fi;
		q.pop();
		if(dd>d[u]) continue;

		for(auto v: adj[u])if(d[v.fi]>dd+v.se){
			d[v.fi]=dd+v.se;
			q.push({d[v.fi],v.fi});
		}
	}

	//d2
	q.push({0,N});
	while(!q.empty()){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>d2[u]) continue;

		for(auto v: adj2[u])if(d2[v.fi]>d+v.se){
			d2[v.fi]=d+v.se;
			q.push({d2[v.fi],v.fi});
		}
	}

	//d3
	q.push({0,N});
	while(!q.empty()){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>d3[u]) continue;

		for(auto v: adj[u])if(d3[v.fi]>d+v.se){
			d3[v.fi]=d+v.se;
			q.push({d3[v.fi],v.fi});
		}
	}

	//d4
	q.push({0,1});
	while(!q.empty()){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>d4[u]) continue;

		for(auto v: adj2[u])if(d4[v.fi]>d+v.se){
			d4[v.fi]=d+v.se;
			q.push({d4[v.fi],v.fi});
		}
	}

	//d5
	q.push({0,1});
	int dist[N+1]; pi p[N+1]; 
	fill(dist,dist+N+1,INF); dist[1]=0;
	FOR(i,1,N+1) p[i]={-1,-1};
	while(!q.empty()){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>dist[u]) continue;

		for(auto v: adj[u])if(dist[v.fi]>d+v.se){
			dist[v.fi]=d+v.se;
			p[v.fi]={u,v.se};
			q.push({dist[v.fi],v.fi});
		}
	}

	vi vc; //edges included in the shortest path (1 --> N)
	int v=N;
	while(p[v].fi!= -1){
		int u=p[v].fi,w=p[v].se;
		vc.pb(mp[{{u,v},w}]);
		v=u;
	}
	
	for(auto i: vc){
		int uu=vec[i].u,vv=vec[i].v;

		q.push({0,1});
		fill(dist,dist+N+1,INF); dist[1]=0;

		while(!q.empty()){
			int u=q.top().se,d=q.top().fi;
			q.pop();
			if(d>dist[u]) continue;

			for(auto v: adj[u])if(!(u==uu && v.fi==vv) && dist[v.fi]>d+v.se){
				dist[v.fi]=d+v.se;
				q.push({dist[v.fi],v.fi});
			}
		}
		d5[i]=dist[N];
	}
	bool inc[M]; fill(inc,inc+M,0); for(auto i: vc) inc[i]=1;
	FOR(i,0,M) if(!inc[i]) d5[i]=d[N];


	//d6
	q.push({0,N});
	fill(dist,dist+N+1,INF); dist[N]=0;
	FOR(i,1,N+1) p[i]={-1,-1};
	while(!q.empty()){
		int u=q.top().se,d=q.top().fi;
		q.pop();
		if(d>dist[u]) continue;

		for(auto v: adj[u])if(dist[v.fi]>d+v.se){
			dist[v.fi]=d+v.se;
			p[v.fi]={u,v.se};
			q.push({dist[v.fi],v.fi});
		}
	}

	vc.clear(); //edges included in the shortest path (N --> 1)
	v=1;
	while(p[v].fi!=-1){
		int u=p[v].fi,w=p[v].se;
		vc.pb(mp[{{u,v},w}]);
		v=u;
	}

	
	for(auto i: vc){
		int uu=vec[i].u,vv=vec[i].v;

		q.push({0,N});
		fill(dist,dist+N+1,INF); dist[N]=0;

		while(!q.empty()){
			int u=q.top().se,d=q.top().fi;
			q.pop();
			if(d>dist[u]) continue;

			for(auto v: adj[u])if(!(u==uu && v.fi==vv)&&dist[v.fi]>d+v.se){
				dist[v.fi]=d+v.se;
				q.push({dist[v.fi],v.fi});
			}
		}
		d6[i]=dist[1];
	}
	fill(inc,inc+M,0); for(auto i: vc) inc[i]=1;
	FOR(i,0,M) if(!inc[i]) d6[i]=d3[1];
}

int32_t main() {
    boost; IO();

    cin>>N>>M;
    FOR(i,0,M){
    	int u,v,w,ww; cin>>u>>v>>w>>ww;
    	vec.pb({u,v,w,ww});
    	adj[u].pb({v,w}); 
    	adj2[v].pb({u,w});
    	mp[{{u,v},w}]=i;
    }

    precompute();

    int ans=d[N]+d3[1];
    FOR(i,0,M){
    	edge ed=vec[i];
    	int u=ed.u,v=ed.v,w=ed.w,ww=ed.ww;
    	swap(u,v); //invert

    	int x=ww+d[u]+w+d2[v]+d6[i];
    	int y=ww+d3[u]+w+d4[v]+d5[i];
    	
    	ckmin(ans,min(x,y));
    }
    if(ans>=1e15) ans=-1;
    cout << ans << endl;
    

    return 0;
}

/*

minDist(N,1)_without an edges
*/

/* Careful!!!
    .Array bounds
    .Infinite loops
    .Uninitialized variables / empty containers
    .Multisets are shit

   Some insights:
    .Binary search
    .Graph representation
    .Write brute force code
    .Change your approach
*/

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 512 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 2 ms 640 KB Output is correct
5 Correct 1 ms 620 KB Output is correct
6 Correct 1 ms 376 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 21 ms 620 KB Output is correct
11 Correct 16 ms 620 KB Output is correct
12 Correct 19 ms 748 KB Output is correct
13 Incorrect 2 ms 620 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 7252 KB Output is correct
2 Correct 41 ms 7260 KB Output is correct
3 Correct 42 ms 7260 KB Output is correct
4 Incorrect 2 ms 620 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 492 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 37 ms 5856 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 42 ms 7508 KB Output is correct
6 Correct 0 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Incorrect 38 ms 7132 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 512 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 2 ms 636 KB Output is correct
4 Correct 2 ms 640 KB Output is correct
5 Correct 1 ms 620 KB Output is correct
6 Correct 1 ms 376 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 21 ms 620 KB Output is correct
11 Correct 16 ms 620 KB Output is correct
12 Correct 19 ms 748 KB Output is correct
13 Incorrect 2 ms 620 KB Output isn't correct
14 Halted 0 ms 0 KB -