Submission #171426

#	Time	Username	Problem	Language	Result	Execution time	Memory
171426		dolphingarlic	Synchronization (JOI13_synchronization)	C++14	100 / 100	984 ms	23928 KiB

synchronization

#include <bits/stdc++.h>
#define F(y)for(int i=1;i<y;i++)
#define x first
#define y second
using namespace std;
const int N=200001;
vector<int> g[N];
pair<int,int> e[N];
int n,m,q,f[N],l[N],t=1,tin[N],tout[N],c[N][20],b[N];
void dfs(int v=1,int p=0){
c[v][0]=p;
F(20)c[v][i]=c[c[v][i - 1]][i - 1];
f[v]=1;
tin[v]=t++;
for(int i : g[v])if(i != p)dfs(i,v);
tout[v]=t;
}
void up(int p,int val){for(; p <= n; p +=(p &(-p)))b[p] += val;}
int qu(int p){
int ans=0;
for(; p; p -=(p &(-p)))ans += b[p];
return ans;
}
int lca(int v){
int ll=v;
for(int i=19;~i;i--)if(c[ll][i]&&qu(tin[c[ll][i]])==qu(tin[v]))ll=c[ll][i];
return ll;
}
main(){
cin >> n >> m >> q;
F(n){
cin >> e[i].x >> e[i].y;
g[e[i].x].push_back(e[i].y);
g[e[i].y].push_back(e[i].x);
}
dfs();
F(n + 1){
up(tin[i],-1);
up(tout[i],1);
}
while(m--){
int x;
cin >> x;
int u=e[x].x,v=e[x].y;
if(c[u][0] == v)swap(u,v);
if(lca(v)!= v){
f[v]=l[v]=f[lca(u)];
up(tin[v],-1);
up(tout[v],1);
} else {
f[lca(u)] += f[v] - l[v];
up(tin[v],1);
up(tout[v],-1);
}
}
while(q--){
int x;
cin >> x;
cout << f[lca(x)] << '\n';
}
}

Compilation message (stderr)

synchronization.cpp:29:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40