Submission #241396

#	Time	Username	Problem	Language	Result	Execution time	Memory
241396		kal013	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	182 ms	160000 KiB

ho_t4

/*/ Author: kal013 /*/
// #pragma GCC optimize ("O3")
#include "bits/stdc++.h"
#include "ext/pb_ds/assoc_container.hpp"
#include "ext/pb_ds/tree_policy.hpp"
using namespace std;
using namespace __gnu_pbds;

template<class T> 
using ordered_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update> ;

template<class key, class value, class cmp = std::less<key>>
using ordered_map = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;
// find_by_order(k)  returns iterator to kth element starting from 0;
// order_of_key(k) returns count of elements strictly smaller than k;

template<class T>
using min_heap = priority_queue<T, vector<T> , greater<T> >;

struct custom_hash { // Credits: https://codeforces.com/blog/entry/62393
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

template<class T> ostream& operator<<(ostream &os, vector<T> V) {
    os << "[ ";
    for(auto v : V) os << v << " ";
    return os << "]";
}
template<class T> ostream& operator<<(ostream &os, set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class T> ostream& operator<<(ostream &os, unordered_set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class T> ostream& operator<<(ostream &os, ordered_set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class L, class R> ostream& operator<<(ostream &os, pair<L,R> P) {
    return os << "(" << P.first << "," << P.second << ")";
}
template<class L, class R> ostream& operator<<(ostream &os, map<L,R> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}
template<class L, class R> ostream& operator<<(ostream &os, unordered_map<L,R> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}
template<class L, class R, class chash = std::hash<R> > ostream& operator<<(ostream &os, gp_hash_table<L,R,chash> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}

#define TRACE
#ifdef TRACE
    #define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template <typename Arg1>
    void __f(const char* name, Arg1&& arg1){
        cerr << name << " : " << arg1 << endl;
    }
    template <typename Arg1, typename... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args){
        const char* comma = strchr(names + 1, ',');
        cerr.write(names, comma - names) << " : " << arg1<<" | ";
        __f(comma+1, args...);
    }
#else
    #define trace(...) 1
#endif

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

inline int64_t random_long(long long l,long long r){
    uniform_int_distribution<int64_t> generator(l,r);
    return generator(rng);
}
inline int64_t random_long(){
    uniform_int_distribution<int64_t> generator(LLONG_MIN,LLONG_MAX);
    return generator(rng);
}


/*/---------------------------Defines----------------------/*/
typedef vector<int> vi;
typedef pair<int,int> pii;

#define ll long long
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(v) (v).begin(),(v).end()
/*/-----------------------Modular Arithmetic---------------/*/

const int mod=1e9+7;
inline int add(int x,int y){
    x+=y;
    if (x>=mod) return x-mod;
    return x;
}
inline int sub(int x,int y){
    x-=y;
    if (x<0) return x+mod;
    return x;
}
inline int mul(int x,int y){
    return (x*1ll*y)%mod;
}
inline int power(int x,int y){
    int ans=1;
    while(y){
        if (y&1) ans=mul(ans,x);
        x=mul(x,x);
        y>>=1;
    }
    return ans;
}
inline int inv(int x){
    return power(x,mod-2);
}
/*/-----------------------------Code begins----------------------------------/*/
const int N = 205;
const int M = 5e4+10;
vector<int> adj[N][2];
const ll INF = 1e15+2;

ll dist[N][N];

ll U[M][2], C[M],D[M];


ll dp[2][N][M][2];


void dijk(int idx,int src,int n,int m){
	assert( idx == 0 || idx == 1);
	assert(src == 1 || src == n);
	int s_id = (src == 1) ? 0 : 1;

	vector<ll> dist(n+3,INF),par(n+3,-1);
	dist[src] = 0;
	min_heap<pair<ll,ll>> queue;
	queue.push({0,src});


	while(!queue.empty()){
		auto X = queue.top();
		queue.pop();
		if (X.first > dist[X.second]) continue;
		// assert(dist[X.second] == X.first);


		for(auto i: adj[X.second][idx]){
			int v = U[i][0]^U[i][1]^X.second;

			if (dist[v] > dist[X.second] + C[i]){
				dist[v] = dist[X.second] + C[i];
				queue.push({dist[v],v});
				par[v] = i;
			}

		}
	}


	vector<bool> vis(m+4,false);
	vector<int> used, unused;

	for(auto e: par){
		if (e != -1) {
			assert(0 <= e && e < m); 
			used.push_back(e); 
			vis[e] = true;
		}
	}
	for(int i = 0; i<m ;++i){
		if (!vis[i]){
			unused.push_back(i);
		}
	}

	for(auto e: unused){
		for(int z = 1; z <= n; ++z){
			dp[idx][z][e][s_id] = dist[z];
		}
	}

	assert(used.size() + unused.size() == m);
	vector<vector<int> > g(n+1);

	for(int i = 1; i <= n; ++i){
		if (par[i] != -1){
			assert(0 <= par[i] && par[i] < m);
			int u = U[par[i]][0]^U[par[i]][1]^i;
			g[u].push_back(i);
		}
	}
	for(auto e: used){


		int u = U[e][0], v = U[e][1];
		if (par[u] == e){
			swap(u,v);
		}
		assert(par[v] == e);
		vector<ll> cur_dist(n+1,INF);
		cur_dist[src] = 0;


		// vector<int> bfs;
		// bfs.push_back(v);

		// for(int iter = 0 ; iter < bfs.size(); ++iter){
		// 	int cu = bfs[iter];
		// 	cur_dist[cu] = INF;

		// 	for(auto e:g[cu]){
		// 		bfs.push_back(e);
		// 		assert(cur_dist[e] < INF);
		// 	} 

		// }

		
		min_heap<pair<ll,ll> > cq;

		for(int i = 1; i<=n ;++ i){
			if (cur_dist[i] < INF){
				cq.push({cur_dist[i],i});
			}
		}


		while(!cq.empty()){
			auto X = cq.top();
			cq.pop();
			if (X.first > cur_dist[X.second]) continue;

			assert(cur_dist[X.second] == X.first);

			for(auto i: adj[X.second][idx]){
				if (i == e) continue;
				
				int v = U[i][0]^U[i][1]^X.second;

				if (cur_dist[v] > cur_dist[X.second] + C[i]){
					cur_dist[v] = cur_dist[X.second] + C[i];
					cq.push({cur_dist[v],v});
				}

			}
		}


		for(int z = 1; z <= n; ++z){
			dp[idx][z][e][s_id] = cur_dist[z];
		}
	}




}

void solve(){
    int n,m;
    cin>>n>>m;
    assert( n < N && m < M);
    for(int i = 1; i<=n ; ++i){
    	for(int j = 1; j<=n ; ++j){
    		dist[i][j] = INF;
    	}
    	dist[i][i] = 0;
    }

    for(int i = 0; i < m; ++i){
    	cin>>U[i][0]>>U[i][1]>>C[i]>>D[i];
    	ll u = U[i][0], v = U[i][1];

    	assert(1 <= u && u <= n && 1 <= v && v <= n);
    	dist[u][v] = min(dist[u][v], C[i]);

    	adj[u][0].push_back(i);
    	adj[v][1].push_back(i);
    }

    for(int mid = 1; mid <= n; ++mid){
    	for(int src = 1; src <= n; ++src){
    		for(int des = 1; des <= n ; ++des){
    			dist[src][des] = min(dist[src][mid] + dist[mid][des],dist[src][des]);
    		}
    	}
    }

    ll ans = min(INF, dist[1][n] + dist[n][1]);
    //dijk(0,1,n,m);
    //dijk(0,n,n,m);
    dijk(1,1,n,m);
    //dijk(1,n,n,m);


    // for(int i = 0; i < m; ++i){
    // 	ll u = U[i][0], v = U[i][1];

    // 	ll cur_s_t = dp[0][n][i][0];
    // 	cur_s_t = min(cur_s_t, dp[0][v][i][0] + dp[1][u][i][1] + C[i]);


    // 	ll cur_t_s = dp[0][1][i][1];

    // 	cur_t_s = min(cur_t_s, dp[0][v][i][1] + dp[1][u][i][0] + C[i]);

    // 	ans = min(ans, cur_t_s + cur_s_t + D[i]);
    // }
    if (ans >= INF){
    	ans = -1;
    }
    cout<<ans<<endl;
}
int main(){
    // Use "set_name".max_load_factor(0.25);"set_name".reserve(512); with unordered set
    // Or use gp_hash_table<X,null_type>
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cout<<fixed<<setprecision(25);
    cerr<<fixed<<setprecision(10);
    auto start = std::chrono::high_resolution_clock::now();
    int t=1;
    // cin>>t;
    while(t--) {
        solve();
    }
    auto stop = std::chrono::high_resolution_clock::now(); 
    auto duration = std::chrono::duration_cast<std::chrono::nanoseconds>(stop - start); 
    
    // cerr << "Time taken : " << ((long double)duration.count())/((long double) 1e9) <<"s "<< endl;     
}

Compilation message (stderr)

In file included from /usr/include/c++/7/ext/pb_ds/detail/pat_trie_/pat_trie_.hpp:45:0,
                 from /usr/include/c++/7/ext/pb_ds/detail/container_base_dispatch.hpp:90,
                 from /usr/include/c++/7/ext/pb_ds/assoc_container.hpp:48,
                 from ho_t4.cpp:4:
ho_t4.cpp: In function 'void dijk(int, int, int, int)':
ho_t4.cpp:208:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  assert(used.size() + unused.size() == m);
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

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