/*
Code written by Talant I.D.
*/
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#include <ext/rope>
//#include <ext/pb_ds/assoc_container.hpp>
//using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;
//typedef tree <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
inline bool isvowel(char ch){
ch = tolower(ch);
return (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u');
}
inline bool isprime(int n){
if(n < 2 || (n%2 == 0 && n != 2)) return false;
for(int i = 3; i*i <= n; i++)
if(n%i == 0) return false;
return true;
}
class Union{
private:
vector <int> saizu, link;
public:
Union(int n){
saizu.assign(n, 1); link.resize(n);
iota(all(link), 0);
}
int find(int n){
if(link[n] == n) return n;
return link[n] = find(link[n]);
}
int same(int a, int b){
return find(a) == find(b);
}
void unite(int a, int b){
if(same(a, b)) return;
a = find(a); b = find(b);
if(saizu[a] < saizu[b]) swap(a, b);
saizu[a] += saizu[b];
link[b] = a;
}
int getsize(int a){
return saizu[find(a)];
}
};
const int mod = 1e9+7;
ll mode(ll a){
a %= mod;
if(a < 0) a += mod;
return a;
}
ll subt(ll a, ll b){
return mode(mode(a)-mode(b));
}
ll add(ll a, ll b){
return mode(mode(a)+mode(b));
}
ll mult(ll a, ll b){
return mode(mode(a)*mode(b));
}
ll binpow(ll a, ll b){
ll res = 1;
while(b){
if(b&1) res = mult(res, a);
a = mult(a, a);
b >>= 1;
}
return res;
}
const int N = 2e5+7;
vector <vector <ll>> graph(N);
ll tin[N], tout[N], timer, up[N][20];
void dfs(int v, int p){
up[v][0] = p;
tin[v] = ++timer;
for(ll i = 1; i < 20; i++){
up[v][i] = up[up[v][i-1]][i-1];
}
for(auto to : graph[v]){
if(to != p){
dfs(to, v);
}
}
tout[v] = ++timer;
}
bool upper(int a, int b){
return tin[a] <= tin[b] && tout[a] >= tout[b];
}
int lca(int a, int b){
if(upper(a, b)) return a;
if(upper(b, a)) return b;
for(ll i = 19; i >= 0; i--){
if(!upper(up[a][i], b)) a = up[a][i];
}
return up[a][0];
}
int main(){
do_not_disturb
ll n, m;
cin >> n >> m;
vector <ll> par(n+1), memory(n+1);
ll root = 1;
for(int i = 1; i <= n; i++){
cin >> par[i] >> memory[i];
if(par[i]){
graph[par[i]].pb(i);
}
else{
root = i;
}
}
dfs(root, root);
if(n < 21 && m < 21){
ll ans = 0;
for(int mask = 0; mask < (1<<n); mask++){
if(__builtin_popcount(mask) != m) continue;
vector <ll> vec;
ll flag = 0, res = 0;
for(ll i = 1; i <= n; i++){
if(mask&(1<<(i-1))){
vec.pb(i);
res += memory[i];
}
}
for(ll i = 0; i < m; i++){
for(ll j = i+1; j < m; j++){
if(upper(vec[i], vec[j]) || upper(vec[j], vec[i])) flag++;
}
}
if(!flag) ans = max(ans, res);
}
cout << ans;
}
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
4 ms |
5100 KB |
Output is correct |
| 2 |
Incorrect |
4 ms |
5100 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
