Submission #313049

#	Time	Username	Problem	Language	Result	Execution time	Memory
313049		jhnah917	Spring cleaning (CEOI20_cleaning)	C++14	100 / 100	393 ms	27632 KiB

cleaning

#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define compress(v) sort(all(v)), v.erase(unique(all(v)), v.end())
using namespace std;

typedef long long ll;

int tree[1 << 18], tmp[1 << 18];
void push(int node, int s, int e){
    if(!tmp[node]) return;
    tree[node] = (e-s+1) - tree[node];
    if(s != e){
        tmp[node << 1] ^= 1;
        tmp[node << 1 | 1] ^= 1;
    }
    tmp[node] = 0;
}
void update(int node, int s, int e, int l, int r){
    push(node, s, e);
    if(r < s || e < l) return;
    if(l <= s && e <= r){ tmp[node] ^= 1; push(node, s, e); return; }
    int m = s + e >> 1;
    update(node << 1, s, m, l, r);
    update(node << 1 | 1, m+1, e, l, r);
    tree[node] = tree[node << 1] + tree[node << 1 | 1];
}
int query(int node, int s, int e, int l, int r){
    push(node, s, e);
    if(r < s || e < l) return 0;
    if(l <= s && e <= r) return tree[node];
    int m = s + e >> 1;
    return query(node << 1, s, m, l, r) + query(node << 1 | 1, m+1, e, l, r);
}

int n, q, leaf[101010];
vector<int> inp[101010], g[101010];
int top[101010], dep[101010], par[101010], sz[101010], in[101010], pv;
void dfs(int v, int b){
    for(auto i : inp[v]) if(i != b) {
        g[v].push_back(i);
        dep[i] = dep[v] + 1; par[i] = v;
        dfs(i, v);
    }
}
void dfs1(int v){
    sz[v] = 1;
    for(auto &i : g[v]){
        dfs1(i); sz[v] += sz[i];
        if(sz[i] > sz[g[v][0]]) swap(i, g[v][0]);
    }
}
void dfs2(int v){
    in[v] = ++pv;
    for(auto i : g[v]){
        top[i] = i == g[v][0] ? top[v] : i;
        dfs2(i);
    }
}
void updatePath(int s, int e){
    for(; top[s]!=top[e]; s=par[top[s]]){
        if(dep[top[s]] < dep[top[e]]) swap(s, e);
        update(1, 1, n, in[top[s]], in[s]);
    }
    if(dep[s] > dep[e]) swap(s, e);
    update(1, 1, n, in[s], in[e]);
}
int getAns(int cnt){
    if(query(1, 1, n, 1, 1)) return -1;
    return 2*(n-1) - query(1, 1, n, 1, n) + cnt;
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    cin >> n >> q;
    for(int i=1; i<n; i++){
        int s, e; cin >> s >> e;
        inp[s].push_back(e); inp[e].push_back(s);
    }
    top[1] = 1; dfs(1, -1); dfs1(1); dfs2(1);
    for(int i=1; i<=n; i++) if(inp[i].size() == 1) leaf[i] = 1, updatePath(1, i);
    while(q--){
        int cnt; cin >> cnt;
        vector<int> add; set<int> st;
        for(int i=0; i<cnt; i++){
            int t; cin >> t;
            if(!leaf[t] || st.count(t)) add.push_back(t);
            st.insert(t);
        }
        for(auto i : add) updatePath(1, i);
        cout << getAns(cnt) << "\n";
        for(auto i : add) updatePath(1, i);
    }
}

Compilation message (stderr)

cleaning.cpp: In function 'void update(int, int, int, int, int)':
cleaning.cpp:24:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   24 |     int m = s + e >> 1;
      |             ~~^~~
cleaning.cpp: In function 'int query(int, int, int, int, int)':
cleaning.cpp:33:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   33 |     int m = s + e >> 1;
      |             ~~^~~

• Subtask 1: 0 / 0
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 19 / 19
• Subtask 6: 17 / 17
• Subtask 7: 30 / 30