Submission #689397

#	Time	Username	Problem	Language	Result	Execution time	Memory
689397		myrcella	Bridges (APIO19_bridges)	C++17	100 / 100	2451 ms	84180 KiB

bridges

//by szh
#include<bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}

const int maxn = 1e6+10;

int n,m,Q;
vector <pii> edge;
vector <pair<pii,int>> upd[maxn],q[maxn];
int ans[maxn];
vector <pii> change[maxn];
int f[maxn],sz[maxn];
vector <pair<int,pii>> hist;
int val[maxn];

int getf(int x) {
	if (f[x]==x) return x;
	else return getf(f[x]);
}

void merge(int u,int v,bool redo) {
	int fu = getf(u),fv = getf(v);
	if (fu==fv) return;
	if (sz[fu]>sz[fv]) swap(fu,fv);
	if (redo) hist.pb({fu,{fv,sz[fv]}});
	f[fu] = fv;
	sz[fv] += sz[fu];
}

bool cmp(int x,int y) {
	return val[x]<val[y];
}

bool cmpp(pair<pii,int> x,pair<pii,int> y) {
	return x.fi.se>y.fi.se;
}

void redoo() {
	while (!hist.empty()) {
		auto tmp = hist.back();
		hist.pop_back();
		f[tmp.fi]=tmp.fi;
		sz[tmp.se.fi] = tmp.se.se;
	}
}

void solve(int cur) {
	rep(i,1,n+1) f[i] = i,sz[i] = 1;
	for (auto i:upd[cur]) change[i.fi.fi].pb({i.se,i.fi.se});
	vector <int> samedge,difedge;
	rep(i,0,m) {
		if (SZ(change[i])==0) samedge.pb(i);
		else difedge.pb(i);
	}
	sort(ALL(samedge),cmp);
	sort(ALL(q[cur]),cmpp);
	for (auto i:q[cur]) {
		while (!samedge.empty() and val[samedge.back()]>=i.fi.se) {
			int idx = samedge.back();
			samedge.pop_back();
			merge(edge[idx].fi,edge[idx].se,false);
		}
		for (int j:difedge) {
			int curval = val[j];
			rep(k,0,SZ(change[j])) {
				if (change[j][k].fi>i.se) break;
				curval = change[j][k].se;
			}
			if (curval>=i.fi.se) merge(edge[j].fi,edge[j].se,true);		
		}
		ans[i.se] = sz[getf(i.fi.fi)];
		redoo();
	}
	for (int j:difedge) {
		val[j] = change[j].back().se;
		while (!change[j].empty()) change[j].pop_back();
	}
}

int main() {
//	freopen("input.txt","r",stdin);	
	memset(ans,-1,sizeof(ans));
	std::ios::sync_with_stdio(false);cin.tie(0);
	cin>>n>>m;
	rep(i,0,m) {
		int u,v,w;
		cin>>u>>v>>w;
		edge.pb({u,v});
		val[i] = w;
	}
	cin>>Q;
	int sz = (int)sqrt(m*log(n)/log(2));
	if (sz==0) sz=1;
	debug(sz);
	rep(i,0,Q) {
		int op,x,y;
		cin>>op>>x>>y;
		if (op==1) {
			x--;
			upd[i/sz].pb({{x,y},i});
		}
		else q[i/sz].pb({{x,y},i});
	}
	rep(i,0,(Q-1)/sz+1) solve(i);
	rep(i,0,Q) {
		if (ans[i]!=-1) cout<<ans[i]<<"\n";
	}
	return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27