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답안 #328613

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
328613 2020-11-17T11:02:06 Z AmineWeslati 경주 (Race) (IOI11_race) C++14
100 / 100
 1305 ms 114652 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"
#ifndef LOCAL
#include "race.h"
#endif
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long 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 = 1e9;
const int MX = 2e5 + 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
}

const int LOG=28;
int N,K;
vi adj[MX]; //for the centroid decomposition
vpi adj0[MX]; //for the initial tree

/*
Precomputations:
	-centroid tree ready in adj[]
	-parent[] (of the centroid tree)
	-dist(u,v)
	-length(u,v)
*/

//LCA precomp
int in[MX],out[MX],cnt=0;
bool ancestor(int u, int v){
	return in[u]<=in[v] && out[u]>=out[v];
}

ll distR[MX],lengthR[MX],jump[MX][LOG];
void precompute_lca(int u, int p){
	in[u]=++cnt;

	jump[u][0]=p;
	FOR(i,1,LOG) jump[u][i]=jump[jump[u][i-1]][i-1];

	if(u==0) distR[u]=lengthR[u]=0;
	for(auto v: adj0[u]) if(v.fi!=p){
		distR[v.fi]=distR[u]+v.se;
		lengthR[v.fi]=lengthR[u]+1;
		precompute_lca(v.fi,u);
	}

	out[u]=++cnt;
}

int LCA(int u, int v){
	if(ancestor(u,v)) return u;
	if(ancestor(v,u)) return v;

	ROF(i,0,LOG) if(!ancestor(jump[u][i],v)) u=jump[u][i];
	return jump[u][0];
}

ll dist(int u, int v){
	return distR[u]+distR[v]-2*distR[LCA(u,v)];
}
ll length(int u, int v){
	return lengthR[u]+lengthR[v]-2*lengthR[LCA(u,v)];
}


//Centroid tree precomp.

bool vis[MX];
int szz[MX];
void find_sizes(int u, int p){
	szz[u]=1;
	for(auto v: adj0[u]) if(v.fi!=p && !vis[v.fi]){
		find_sizes(v.fi,u);
		szz[u]+=szz[v.fi];
	}
}

int find_centroid(int u, int p, int root){
	for(auto v: adj0[u]) if(!vis[v.fi] && v.fi!=p){
		if(szz[v.fi]>szz[root]/2) return find_centroid(v.fi,u,root);
	}
	return u;
}

int parent[MX];
void decompose(int u, int p){
	find_sizes(u,u);
	int c=find_centroid(u,u,u);
	vis[c]=true;

	parent[c]=p; if(p==-1) parent[c]=c;
	if(p!=-1){
		adj[c].pb(p);
		adj[p].pb(c);
	}

	for(auto v: adj0[c]) if(!vis[v.fi]){ 
		decompose(v.fi,c);
	}
}


//Centroid tree
vpi mn(1000001),mn2(1000001);

void revisit(int d, int l, int u){
	if(l<=mn[d].fi){
		if(u!=mn[d].se){
			mn2[d]=mn[d];
			mn[d]={l,u};
		}
		else{
			mn[d]={l,u};
		}
	}
	else if(l<=mn2[d].fi){
		if(u!=mn[d].se){
			mn2[d]={l,u};
		}
	}
}

V<pair<pair<ll,int>,int>> vec; //(dist,length,child_subtree)
void dfs(int u, int p, int child, int lca){
	vec.pb({{dist(u,lca),length(u,lca)},child});
	for(auto v: adj[u]) if(v!=p) dfs(v,u,child,lca);
}

int solve(){ 
	FOR(i,0,K+1) mn[i]=mn2[i]={INF,INF};

	int ans=INF;
	FOR(lca,0,N){
		vec.clear();
		for(auto v: adj[lca]) if(v!=parent[lca]) 
			dfs(v,lca,v,lca);

		for(auto x: vec) if(x.fi.fi<=K){
			revisit(x.fi.fi,x.fi.se,x.se);
		}

		for(auto x: vec) if(x.fi.fi<=K){
			int d=x.fi.fi,l=x.fi.se,u=x.se;
			int v=l;
			if(d!=K){
				int r=K-d;
				if(mn[r].se!=u) v+=mn[r].fi;
				else v+=mn2[r].fi;
			}
			ckmin(ans,v);
		}

		for(auto x: vec) if(x.fi.fi<=K){
			mn[x.fi.fi]=mn2[x.fi.fi]={INF,INF};
		}
	}
	return ans;
}

//main
int best_path(int NN, int KK, int H[][2], int L[]){
	N=NN; K=KK;
	FOR(i,0,N-1){
		int u=H[i][0],v=H[i][1],w=L[i];
		adj0[u].pb({v,w});
		adj0[v].pb({u,w});
	}

	precompute_lca(0,0);
	fill(vis,vis+MX,0);
	decompose(0,-1);

	int ans=solve();
	if(ans==INF) ans=-1;
	return ans;
}

#ifdef LOCAL
int main() {
    boost; IO();

    cin>>N>>K;
    int h[N-1][2];
    int l[N-1];
    FOR(i,0,N-1) cin>>h[i][0]>>h[i][1];
    FOR(i,0,N-1) cin>>l[i];
    cout << best_path(N,K,h,l) << endl;
    

    return 0;
}
#endif

/*
11 12 
0 1
0 2
2 3
3 4
4 5
0 6
6 7
6 8
8 9
8 10
3 4 5 4 6 3 2 5 6 7

2
*/

/*
4 3
0 1
1 2
1 3	
1 2 4

2
*/

/*
-Do centroid decomp.
-for each lca in the centroid tree, 
	.compute dist(lca, u) and length(lca, u) for all u in the subtree of lca
	.for every x=dist(lca, u) assign the min(length(lca,u)) 
	and second min (such that mn and mn2 are from a different child_subtree)
	.for every x=dist(lca, u) assign the minimum length of y=K-x st x & y not from
	the same child_subtree
	(don't forget to reinitialize the min array)
*/

/* 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
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 25640 KB Output is correct
2 Correct 15 ms 25708 KB Output is correct
3 Correct 19 ms 25708 KB Output is correct
4 Correct 19 ms 25708 KB Output is correct
5 Correct 21 ms 25708 KB Output is correct
6 Correct 16 ms 25708 KB Output is correct
7 Correct 16 ms 25708 KB Output is correct
8 Correct 16 ms 25708 KB Output is correct
9 Correct 17 ms 25708 KB Output is correct
10 Correct 16 ms 25728 KB Output is correct
11 Correct 16 ms 25708 KB Output is correct
12 Correct 16 ms 25708 KB Output is correct
13 Correct 89 ms 25708 KB Output is correct
14 Correct 16 ms 25708 KB Output is correct
15 Correct 18 ms 25708 KB Output is correct
16 Correct 56 ms 25716 KB Output is correct
17 Correct 18 ms 25708 KB Output is correct
18 Correct 16 ms 25708 KB Output is correct

Subtask #2
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 25640 KB Output is correct
2 Correct 15 ms 25708 KB Output is correct
3 Correct 19 ms 25708 KB Output is correct
4 Correct 19 ms 25708 KB Output is correct
5 Correct 21 ms 25708 KB Output is correct
6 Correct 16 ms 25708 KB Output is correct
7 Correct 16 ms 25708 KB Output is correct
8 Correct 16 ms 25708 KB Output is correct
9 Correct 17 ms 25708 KB Output is correct
10 Correct 16 ms 25728 KB Output is correct
11 Correct 16 ms 25708 KB Output is correct
12 Correct 16 ms 25708 KB Output is correct
13 Correct 89 ms 25708 KB Output is correct
14 Correct 16 ms 25708 KB Output is correct
15 Correct 18 ms 25708 KB Output is correct
16 Correct 56 ms 25716 KB Output is correct
17 Correct 18 ms 25708 KB Output is correct
18 Correct 16 ms 25708 KB Output is correct
19 Correct 15 ms 25580 KB Output is correct
20 Correct 18 ms 25708 KB Output is correct
21 Correct 18 ms 25964 KB Output is correct
22 Correct 60 ms 26000 KB Output is correct
23 Correct 19 ms 25964 KB Output is correct
24 Correct 20 ms 26044 KB Output is correct
25 Correct 20 ms 25964 KB Output is correct
26 Correct 18 ms 25964 KB Output is correct
27 Correct 89 ms 25964 KB Output is correct
28 Correct 17 ms 25964 KB Output is correct
29 Correct 86 ms 26040 KB Output is correct
30 Correct 19 ms 25964 KB Output is correct
31 Correct 19 ms 25964 KB Output is correct
32 Correct 19 ms 25964 KB Output is correct
33 Correct 21 ms 25964 KB Output is correct
34 Correct 19 ms 25964 KB Output is correct
35 Correct 19 ms 25964 KB Output is correct
36 Correct 22 ms 25964 KB Output is correct
37 Correct 23 ms 25964 KB Output is correct
38 Correct 21 ms 26092 KB Output is correct

Subtask #3
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 25640 KB Output is correct
2 Correct 15 ms 25708 KB Output is correct
3 Correct 19 ms 25708 KB Output is correct
4 Correct 19 ms 25708 KB Output is correct
5 Correct 21 ms 25708 KB Output is correct
6 Correct 16 ms 25708 KB Output is correct
7 Correct 16 ms 25708 KB Output is correct
8 Correct 16 ms 25708 KB Output is correct
9 Correct 17 ms 25708 KB Output is correct
10 Correct 16 ms 25728 KB Output is correct
11 Correct 16 ms 25708 KB Output is correct
12 Correct 16 ms 25708 KB Output is correct
13 Correct 89 ms 25708 KB Output is correct
14 Correct 16 ms 25708 KB Output is correct
15 Correct 18 ms 25708 KB Output is correct
16 Correct 56 ms 25716 KB Output is correct
17 Correct 18 ms 25708 KB Output is correct
18 Correct 16 ms 25708 KB Output is correct
19 Correct 384 ms 63328 KB Output is correct
20 Correct 390 ms 63268 KB Output is correct
21 Correct 367 ms 63072 KB Output is correct
22 Correct 344 ms 63456 KB Output is correct
23 Correct 346 ms 63520 KB Output is correct
24 Correct 232 ms 63672 KB Output is correct
25 Correct 479 ms 66524 KB Output is correct
26 Correct 233 ms 70624 KB Output is correct
27 Correct 337 ms 100064 KB Output is correct
28 Correct 1183 ms 114244 KB Output is correct
29 Correct 1207 ms 112988 KB Output is correct
30 Correct 349 ms 100180 KB Output is correct
31 Correct 351 ms 100152 KB Output is correct
32 Correct 599 ms 100060 KB Output is correct
33 Correct 1010 ms 98396 KB Output is correct
34 Correct 1031 ms 98268 KB Output is correct

Subtask #4
57.0 / 57.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 25640 KB Output is correct
2 Correct 15 ms 25708 KB Output is correct
3 Correct 19 ms 25708 KB Output is correct
4 Correct 19 ms 25708 KB Output is correct
5 Correct 21 ms 25708 KB Output is correct
6 Correct 16 ms 25708 KB Output is correct
7 Correct 16 ms 25708 KB Output is correct
8 Correct 16 ms 25708 KB Output is correct
9 Correct 17 ms 25708 KB Output is correct
10 Correct 16 ms 25728 KB Output is correct
11 Correct 16 ms 25708 KB Output is correct
12 Correct 16 ms 25708 KB Output is correct
13 Correct 89 ms 25708 KB Output is correct
14 Correct 16 ms 25708 KB Output is correct
15 Correct 18 ms 25708 KB Output is correct
16 Correct 56 ms 25716 KB Output is correct
17 Correct 18 ms 25708 KB Output is correct
18 Correct 16 ms 25708 KB Output is correct
19 Correct 15 ms 25580 KB Output is correct
20 Correct 18 ms 25708 KB Output is correct
21 Correct 18 ms 25964 KB Output is correct
22 Correct 60 ms 26000 KB Output is correct
23 Correct 19 ms 25964 KB Output is correct
24 Correct 20 ms 26044 KB Output is correct
25 Correct 20 ms 25964 KB Output is correct
26 Correct 18 ms 25964 KB Output is correct
27 Correct 89 ms 25964 KB Output is correct
28 Correct 17 ms 25964 KB Output is correct
29 Correct 86 ms 26040 KB Output is correct
30 Correct 19 ms 25964 KB Output is correct
31 Correct 19 ms 25964 KB Output is correct
32 Correct 19 ms 25964 KB Output is correct
33 Correct 21 ms 25964 KB Output is correct
34 Correct 19 ms 25964 KB Output is correct
35 Correct 19 ms 25964 KB Output is correct
36 Correct 22 ms 25964 KB Output is correct
37 Correct 23 ms 25964 KB Output is correct
38 Correct 21 ms 26092 KB Output is correct
39 Correct 384 ms 63328 KB Output is correct
40 Correct 390 ms 63268 KB Output is correct
41 Correct 367 ms 63072 KB Output is correct
42 Correct 344 ms 63456 KB Output is correct
43 Correct 346 ms 63520 KB Output is correct
44 Correct 232 ms 63672 KB Output is correct
45 Correct 479 ms 66524 KB Output is correct
46 Correct 233 ms 70624 KB Output is correct
47 Correct 337 ms 100064 KB Output is correct
48 Correct 1183 ms 114244 KB Output is correct
49 Correct 1207 ms 112988 KB Output is correct
50 Correct 349 ms 100180 KB Output is correct
51 Correct 351 ms 100152 KB Output is correct
52 Correct 599 ms 100060 KB Output is correct
53 Correct 1010 ms 98396 KB Output is correct
54 Correct 1031 ms 98268 KB Output is correct
55 Correct 34 ms 29612 KB Output is correct
56 Correct 33 ms 29616 KB Output is correct
57 Correct 175 ms 63456 KB Output is correct
58 Correct 97 ms 64220 KB Output is correct
59 Correct 196 ms 70624 KB Output is correct
60 Correct 1177 ms 114652 KB Output is correct
61 Correct 340 ms 101648 KB Output is correct
62 Correct 336 ms 101340 KB Output is correct
63 Correct 602 ms 101440 KB Output is correct
64 Correct 1031 ms 101588 KB Output is correct
65 Correct 809 ms 102236 KB Output is correct
66 Correct 1305 ms 111960 KB Output is correct
67 Correct 320 ms 104024 KB Output is correct
68 Correct 591 ms 101592 KB Output is correct
69 Correct 610 ms 102376 KB Output is correct
70 Correct 534 ms 98520 KB Output is correct