Submission #701645

#	Time	Username	Problem	Language	Result	Execution time	Memory
701645		sugartheanh	Synchronization (JOI13_synchronization)	C++14	30 / 100	84 ms	23792 KiB

synchronization

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

#define dbg(x) cerr << #x << ": " << x << endl;
#define ii pair<int,int>
#define fi first
#define se second
const int MOD = 1e9 + 7;
const int N = 2e5 + 5;
int n,m,q,d[N],first[N],ans = 0;
vector<ii>p[N],c[N];
bool on[N];
int getpos(int k,int last)
{
    int l = 0,r = c[k].size()-1;
    int pos = -1;
    while(l <= r)
    {
        int mid = l + r >> 1;
        if(c[k][mid].fi < last)
        {
            pos = mid;
            l = mid + 1;
        }
        else
            r = mid - 1;
    }
    return pos;
}
void dfs(int x,int u,int last)
{
    ans++;
    for(auto v : p[u])
    {
        if(v.fi == x)
            continue;
        int pos = getpos(v.se, last);
        if(pos == -1)
            continue;
        dfs(u,v.fi ,min(last, c[v.se][pos].se));
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>n>>m>>q;
    for(int i = 1;i < n;i++)
    {
        int u,v;
        cin>>u>>v;
        p[u].push_back(ii(v,i));
        p[v].push_back(ii(u,i));
    }
    for(int i = 1;i <= m;i++)
    {
        int x;
        cin>>x;
        if(!on[x])
            first[x] = i;
        else
            c[x].push_back(ii(first[x], i));
        on[x] ^= 1;
    }
    for(int i = 1;i < n;i++)
    {
        if(on[i])
            c[i].push_back(ii(first[i], m+1));
    }
    while(q--)
    {
        int root;
        cin>>root;
        dfs(0,root,m+1);
        cout<<ans;
    }
    return 0;
}

Compilation message (stderr)

synchronization.cpp: In function 'int getpos(int, int)':
synchronization.cpp:19:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |         int mid = l + r >> 1;
      |                   ~~^~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40