Submission #333248

#	Time	Username	Problem	Language	Result	Execution time	Memory
333248		aloo123	Factories (JOI14_factories)	C++14	0 / 100	2880 ms	102124 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"


using namespace std;
using ll = long long;
using pl = pair<ll,ll>;
using vl = vector<ll>; 
#define mp make_pair
#define f first
#define s second
 
// vectors
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define ins insert 
#define pf push_front 
#define pb push_back
 
// loops
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
 
const int MOD = 1e9+7; // 998244353;
const int INF = 1e9; // not too close to LLONG_MAX

// #define int ll
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; // for every grid problem!!
const int MAXN = 1e6+5;
const int LOGN = 25;

int n,current_tree = 0;
vector<pl> g[MAXN];
int best[MAXN],deleted[MAXN];
int depth[MAXN];
int par[MAXN],sub[MAXN];
int dist[LOGN][MAXN];
// initally all nodes are red

int LCA(int u,int v){
	// finds LCA in of u and v in the centroid tree
	while(u != v){
		if(depth[u] < depth[v])
			v = par[v]; // get v a level up
		else
			u = par[u]; // get u a level up
	}
	return u;
}
int compute_dist(int x,int y){
	int lc = depth[LCA(x,y)];
	return dist[lc][x] + dist[lc][y];
}
void find_subtree(int u,int p){
	sub[u] = 1;
	current_tree++;
	trav(P,g[u]){
		int v = P.f;
		if(deleted[v] == 0 && v != p){
			find_subtree(v,u);
			sub[u] += sub[v];
		}
	}
}
int find_centroid(int u,int p){
	trav(P,g[u]){
		int v = P.f;
		if(deleted[v] == 0 && v !=p  && sub[v] > (current_tree / 2)) return find_centroid(v,u);
	}
	return u;
}
void dfs(int u,int p,int lvl,int dd){
	dist[lvl][u] = dd;
	trav(P,g[u]){
		int v = P.f;
		int w = P.s;
		if(deleted[v] == 0 && v != p){
			dfs(v,u,lvl,dd + w);
		}
	}
}
void decompose(int root,int p){
	current_tree = 0;
	find_subtree(root,p);
	int cen = find_centroid(root,p);
	par[cen] = p;
	if(p != -1) depth[cen] = depth[p] + 1;
	dfs(cen,p,depth[cen],0);
	deleted[cen] = 1;
	trav(P,g[cen]){
		int v = P.f;
		if(deleted[v] == 1) continue;
		decompose(v,cen);
	}
}

int query(int u){
	// find the nearest blue node to u
	int ans = best[u];
	int x = u;
	u = par[u];
	while(u != -1){
		ans = min(ans,compute_dist(x,u) + best[u]);
		u = par[u];
    }
	return ans;
}
void update(int u){
	// colour node u to blue
	int x = u;
	while(u != -1){
		best[u] = min(best[u],compute_dist(u,x));
		u = par[u];
	}
}
void remove_col(int u){
	// u has to be a blue node
	// remove its colour
	while(u != -1){
		best[u] = INF;
		u = par[u];
	}
}

void Init(int N, int A[], int B[], int D[]) {
	n = N;
	FOR(i,0,n-1){A[i]++,B[i]++;
		g[A[i]].pb(mp(B[i],D[i]));
		g[B[i]].pb(mp(A[i],D[i]));
	}

	for(int i =1;i<=n;i++) best[i] = INF;
	decompose(1,-1);
}

long long Query(int S, int X[], int T, int Y[]) {
	for(int i =0;i<S;i++) X[i]++;
	for(int i =0;i<T;i++) Y[i]++;
    for(int i = 0;i < T;i++){
		update(Y[i]);
    }
    int ans = INF;
	for(int i = 0;i< S;i++){
		ans = min(ans,query(X[i]));
	}
	for(int i =0;i<T;i++){
		remove_col(Y[i]);
	}
	return ans;
}

/* void solve(){
	cin >> n;
	int q;
	cin >> q;
	FOR(i,2,n+1){
		int u,v,w;
		cin >> u >> v >> w;
		u++,v++;
		g[u].pb(mp(v,w));
		g[v].pb(mp(u,w));	
	}
	for(int i =1;i<=n;i++) best[i] = INF;
	decompose(1,-1);
	FOR(i,1,n+1){
		cout << i << " " << par[i] << endl;
	}
	while(q--){
		int s,t;
		cin >> s >> t;
		vl u(s),v(t);
		for(int i =0;i<s;i++) cin >> u[i],u[i]++;
		for(int i =0;i<t;i++) cin >> v[i],v[i]++;
		for(int i = 0;i < t;i++){
			update(v[i]);
		}
		int ans = INF;
		for(int i = 0;i< s;i++){
			ans = min(ans,query(u[i]));
		}
		cout << ans << endl;
		for(int i =0;i<t;i++){
			remove_col(v[i]);
		}
	}
}	
signed main() {
	cin.tie(0)->sync_with_stdio(0);

	// you should actually read the stuff at the bottom
	int t=1;
	// cin >> t;
	while(t--){
		solve();
	}
} */
/* stuff you should look for
	* read the probem 3 more times in case of WA :)
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
	* DON'T GET STUCK ON ONE APPROACH
*/

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67