Submission #128228

#	Time	Username	Problem	Language	Result	Execution time	Memory
128228		fefe	Bridges (APIO19_bridges)	C++17	14 / 100	3072 ms	10472 KiB

bridges

#include<bits/stdc++.h>
#define MAX_N 500005
#define MAX_M 1000005
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(),(v).end()
using namespace std;
typedef long long LL;
typedef long double LD;
typedef pair<int,int> pii;
typedef pair<LL,LL> pil;
struct edge{
	int x,y,v;
}E[MAX_M],Q[MAX_M];
struct node{
	int t,i,b,a;
};
struct infor{
	int x,y,hx,hy,ex,ey;
};
int n,m;
int qn;
int par[MAX_N],height[MAX_N],ea[MAX_N];
bool chk[MAX_M];
const int b=50000;
vector<edge> e;
vector<node> lst;
vector<pii> ans;
stack<infor> st;
int find_par(int x){return par[x]==x?x:find_par(par[x]);}
void init(){
	for(int i=1;i<=n;i++){
		par[i]=i;
		height[i]=ea[i]=1;
	}
}
int merge(int x,int y){
	int p=find_par(x);
	int q=find_par(y);
	if(p==q)	return 0;
	st.push({p,q,height[p],height[q],ea[p],ea[q]});
	if(height[p]>height[q]){
		ea[p]+=ea[q];
		par[q]=p;
	}else{
		if(height[p]==height[q])	height[q]++;
		ea[q]+=ea[p];
		par[p]=q;
	}
	return 1;
}
void _back(int cnt){
	while(st.size() && cnt--){
		infor p = st.top();
		par[p.x]=p.x;par[p.y]=p.y;
		height[p.x]=p.hx;height[p.y]=p.hy;
		ea[p.x]=p.ex;ea[p.y]=p.ey;
		st.pop();
	}
	while(st.size())	st.pop();
}
void solve(int k){
	for(int i=1;i<=m;i++)	chk[i]=false;
	for(int i=0;i<qn;i++){
		if(Q[i].v==1){
			chk[Q[i].x]=true;
			lst.pb({i,Q[i].x,E[Q[i].x].v,Q[i].y});
			Q[i].v=-1;
		}else	Q[i].v=i;
	}
	e.clear();e.resize(0);
	for(int i=1;i<=m;i++){
		if(!chk[i])	e.pb(E[i]);
	}
	sort(Q,Q+qn,[&](const edge x,const edge y){
		if(x.v==-1)		return false;
		if(y.v==-1)	return true;
		return (x.y>y.y);
	});
	sort(all(e),[&](const edge x,const edge y){return x.v>y.v;});
	init();
	int p=0;
	for(int i=0;i<qn;i++){
		edge ques = Q[i];
		if(ques.v==-1)	break;
		int cn=0;
		for(;p<e.size() && e[p].v>=ques.y;p++)	merge(e[p].x,e[p].y);
		
		for(node ne:lst){
			int x=E[ne.i].x;
			int y=E[ne.i].y;
			int v;
			if(ne.t>ques.v)	v=ne.b;
			else	v=ne.a;
			
			if(v>=ques.y)	cn+=merge(x,y);
		}
		ans.pb({k+ques.v,ea[find_par(ques.x)]});
		_back(cn);
	}
	for(node ne:lst)	E[ne.i].v=ne.a;
	qn=0;
}
int main(){
	int i;
	scanf("%d %d",&n,&m);
	for(i=1;i<=m;i++)	scanf("%d %d %d",&E[i].x,&E[i].y,&E[i].v);
	int q;scanf("%d",&q);
	for(i=1;i<=q;i++){
		scanf("%d %d %d",&Q[qn].v,&Q[qn].x,&Q[qn].y);qn++;
		if(qn==b)	solve(i);
	}
	solve(i);
	sort(all(ans));
	for(pii print:ans)	printf("%d\n",print.se);
	return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'void solve(int)':
bridges.cpp:89:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(;p<e.size() && e[p].v>=ques.y;p++) merge(e[p].x,e[p].y);
        ~^~~~~~~~~
bridges.cpp: In function 'int main()':
bridges.cpp:108:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
bridges.cpp:109:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1;i<=m;i++) scanf("%d %d %d",&E[i].x,&E[i].y,&E[i].v);
                    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bridges.cpp:110:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int q;scanf("%d",&q);
        ~~~~~^~~~~~~~~
bridges.cpp:112:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d",&Q[qn].v,&Q[qn].x,&Q[qn].y);qn++;
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 14 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27