Submission #756963

#	Time	Username	Problem	Language	Result	Execution time	Memory
756963		Sam_a17	Spring cleaning (CEOI20_cleaning)	C++17	54 / 100	554 ms	37624 KiB

cleaning

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
// #include <atcoder/all>
#include <cstdio>
using namespace std;
 
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
 
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
 
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
 
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
void print(long double t) {cerr << t;}
 
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T> void print(T v[],T n) {cerr << "["; for(int i = 0; i < n; i++) {cerr << v[i] << " ";} cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
 
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
 
long long ka() {
	long long x = 0;
	bool z = false;
	while (1)
	{
		char y = getchar();
		if (y == '-')
			z = true;
		else if ('0' <= y && y <= '9')
			x = x * 10 + y - '0';
		else
		{
			if (z)
				x *= -1;
			return x;
		}
	}
}
 
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();
 
  // if (str != "") {
  //   freopen((str + ".in").c_str(), "r", stdin);
  //   freopen((str + ".out").c_str(), "w", stdout);
  // }else {
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
  // }
}
 
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 4e5 + 10, M = 7e6 + 10;
vector<int> adj[N];
int n, q, deg[N];

int dp[N][3];
int add[N], depth[N];
int two[N];
bool is_leaf[N];

int sz[N], id[N], tp[N], p[N], dep[N];
struct node {
  long long ones, twos, lazy;
};

node combine(node a, node b) {
  a.ones += b.ones;
  a.twos += b.twos;
  a.lazy = 0;
  return a;
}

struct segTree {

  vector<node> tree;
  int size = 1;
 

  void propagate(int x, int lx, int rx) {
    if(rx - lx == 1 || tree[x].lazy % 2 == 0) {
      tree[x].lazy = 0;
      return;
    }
 
    int mid = (lx + rx) / 2;
 
    tree[2 * x + 1].lazy += tree[x].lazy;
    swap(tree[2 * x + 1].ones, tree[2 * x + 1].twos);
 
    tree[2 * x + 2].lazy += tree[x].lazy;
    swap(tree[2 * x + 2].ones, tree[2 * x + 2].twos);
 
    tree[x].lazy = 0;
  }
 
  void init(long long s) {
    while(size < s) {
      size *= 2;
    }
    tree.assign(2 * size - 1, {0, 0, 0});
  }
 
  void upd(int l, int r, long long value, int x, int lx, int rx) {
    propagate(x, lx, rx);
    if(lx >= r || rx <= l) {
      return;
    }
 
    if(lx >= l && rx <= r) {
      if(value % 2 == 1) {
        swap(tree[x].ones, tree[x].twos);
      }
      tree[x].lazy += value;
      propagate(x, lx, rx);
      return;
    }
 
    int mid = (lx + rx) / 2;
    upd(l, r, value, 2 * x + 1, lx, mid);
    upd(l, r, value, 2 * x + 2, mid, rx);
    tree[x] = combine(tree[2 * x + 1], tree[2 * x + 2]);
  }
 
  void upd(int l, int r, long long value) {
    upd(l, r, value, 0, 0, size);
  }

  void upd2(int l, int r, long long value, int x, int lx, int rx) {
    propagate(x, lx, rx);
    if(lx >= r || rx <= l) {
      return;
    }
 
    if(lx >= l && rx <= r) {
      if(value == 1) {
        tree[x].ones = 1;
      } else {
        tree[x].twos = 1;
      }
      propagate(x, lx, rx);
      return;
    }
 
    int mid = (lx + rx) / 2;
    upd2(l, r, value, 2 * x + 1, lx, mid);
    upd2(l, r, value, 2 * x + 2, mid, rx);
    tree[x] = combine(tree[2 * x + 1], tree[2 * x + 2]);
  }
 
  void upd2(int l, int r, long long value) {
    upd2(l, r, value, 0, 0, size);
  }
 
  node qry(int l, int r, int x, int lx, int rx) {
    propagate(x, lx, rx);
    if(lx >= r || rx <= l) {
      return {0, 0, 0};
    }
 
    if(lx >= l && rx <= r) {
      return tree[x];
    }
 
    int mid = (lx + rx) / 2;
    node s1 = qry(l, r, 2 * x + 1, lx, mid);
    node s2 = qry(l, r, 2 * x + 2, mid, rx);
    return combine(s1, s2);
  }
 
  node qry(int l, int r) {
    return qry(l, r, 0, 0, size);
  }
};
segTree seg;

int dfs_sz(int cur, int par) {
	sz[cur] = 1;
	p[cur] = par;
	for (int chi : adj[cur]) {
		if (chi == par) continue;
		dep[chi] = dep[cur] + 1;
		p[chi] = cur;
		sz[cur] += dfs_sz(chi, cur);
	}
	return sz[cur];
}

int ct = 1;

void dfs_hld(int cur, int par, int top) {
	id[cur] = ct++;
	tp[cur] = top;

  if(dp[cur][2] != -1) {
    seg.upd2(id[cur], id[cur] + 1, 2);
  } else {
    seg.upd2(id[cur], id[cur] + 1, 1);
  }


	int h_chi = -1, h_sz = -1;
	for (int chi : adj[cur]) {
		if (chi == par) continue;
		if (sz[chi] > h_sz) {
			h_sz = sz[chi];
			h_chi = chi;
		}
	}
	if (h_chi == -1) return;
	dfs_hld(h_chi, cur, top);
	for (int chi : adj[cur]) {
		if (chi == par || chi == h_chi) continue;
		dfs_hld(chi, cur, chi);
	}
}

node path(int a, int b) {
  node answ = {0, 0, 0};
  while(tp[a] != tp[b]) {
    node curr = seg.qry(id[tp[a]], id[a] + 1);
    answ = combine(answ, curr);
    a = p[tp[a]];
  }
 
  //
  node curr = seg.qry(id[b], id[a] + 1);
  answ = combine(answ, curr);
  return answ;
}

void change_path(int a, int b) {
  while(tp[a] != tp[b]) {
    seg.upd(id[tp[a]], id[a] + 1, 1);
    a = p[tp[a]];
  }
  //
  seg.upd(id[b], id[a] + 1, 1);
}


void dfs(int node, int parent) {
  dp[node][1] = dp[node][2] = -1;

  int cnt = 0;
  for(auto i: adj[node]) {
    if(i == parent) continue;
    cnt++;
    dfs(i, node);
  }

  cnt += add[node];

  if(!cnt) {
    dp[node][1] = 0;
    is_leaf[node] = 1;
  } else {
    long long s = 0, c = 0;
    for(auto i: adj[node]) {
      if(i == parent) continue;

      if(dp[i][1] != -1) {
        c += 1;
        s += dp[i][1] + 1;
      } else if(dp[i][2] != -1) {
        c += 2;
        s += dp[i][2] + 2;
      }
    }

    s += add[node];
    c += add[node];

    if(c & 1) {
      dp[node][1] = s;
    } else {
      dp[node][2] = s;
    }
  }

  add[node] = 0;
}

void dfs2(int node, int parent) {
  if(parent) {
    two[node] += two[parent];
    depth[node] = depth[parent] + 1;
    if(dp[node][2] != -1) {
      two[node]++;
    }  
  }
  
  for(auto i: adj[node]) {
    if(i == parent) continue;
    dfs2(i, node);
  }
}

int slv(int start, int a) {
  int ans = dp[start][1];
  for(int i = 1; i <= 1; i++) {

    if(is_leaf[a]) {
      
      if(dp[start][2] == -1) {
        ans = -1;
      } else {
        ans = dp[start][2] + 1;
      }

      break;
    } else if(ans == -1) {
      break;
    }

    ans += 1;
    ans -= two[a];
    ans += depth[a] - two[a];
  }

  return ans;
}

void solve_() {
  cin >> n >> q;
  // n = ka(), q = ka();

  for(int i = 1; i <= n - 1; i++) {
    int a, b; 
    // a = ka(), b = ka();
    cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);

    deg[a]++, deg[b]++;
  }

  int start = -1;
  for(int i = 1; i <= n; i++) {
    if(deg[i] > 1) {
      start = i;
      break;
    }
  }

  seg.init(2 * n + 10);
  dfs(start, 0);
  dfs2(start, 0);
  dfs_sz(start, 0);
  dfs_hld(start, 0, 1);

  while(q--) {
    int d;
    cin >> d;

    long long cur = 0, ans = 0;
    int cr = 0;
    if(dp[start][1] != -1) {
      ans = dp[start][1];
      cur = 1;
    } else {
      ans = dp[start][2];
      cur = 2;
    }

    vector<int> vec;
    vector<pair<int, int>> don;
    int ok = 0;
    for(int i = 1; i <= d; i++) {
      int a; cin >> a, cr = a;
      vec.push_back(a);
      deg[a]++;

      if(a == start) {
        ans += 1;
        change_path(a, start);
        don.push_back({a, start});
        cur++;
        ok = 1;
        continue;
      } else if(deg[a] == 2) {
        ans += 1;
        ok = 1;
        continue;
      }

      cur++;

      auto u = path(a, start);
      auto uu = path(start, start);
      assert(uu.ones <= 1);
      assert(uu.twos <= 1);

      u.ones -= uu.ones;
      u.twos -= uu.twos;

      // assert(u.twos == two[a]);
      assert(u.ones == (depth[a] - u.twos));
      // u.ones = depth[a] - u.twos;

      ans += 1;
      ans -= u.twos;
      ans += u.ones;

      change_path(a, start);
      don.push_back({a, start});
    }

    if(cur % 2 == 1) { 
      cout << -1 << '\n';
    } else {
      cout << ans << '\n';
    }

    for(auto i: vec) {
      deg[i]--;
    }

    for(auto i: don) {
      change_path(i.first, i.second);
    }
  }
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };
 
  int test_cases = 1; 
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
}

Compilation message (stderr)

cleaning.cpp: In member function 'void segTree::propagate(int, int, int)':
cleaning.cpp:131:9: warning: unused variable 'mid' [-Wunused-variable]
  131 |     int mid = (lx + rx) / 2;
      |         ^~~
cleaning.cpp: In function 'void solve_()':
cleaning.cpp:402:9: warning: variable 'cr' set but not used [-Wunused-but-set-variable]
  402 |     int cr = 0;
      |         ^~
cleaning.cpp:413:9: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
  413 |     int ok = 0;
      |         ^~

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