| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1182116 | countless | Friend (IOI14_friend) | C++20 | 0 ms | 0 KiB |
#include "friend.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const ll MOD = 998244353;
const ll INF = 1e18;
const ld EPS = 1e-12;
#define endl "\n"
#define sp <<" "<<
#define REP(i, a, b) for(ll i = a; i < b; i++)
#define dbg(x) cout << #x << " = " << x << endl
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
// http://xorshift.di.unimi.it/splitmix64.c
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
template <typename Key, typename Value>
using hash_map = unordered_map<Key, Value, custom_hash>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// uniform_int_distribution<int>(a, b)(rng);
// shuffle(all(a), rng);
int findSample(int n, int confidence[], int host[], int protocol[]) {
vector<pair<int, int>> dp(n);
REP(i, 0, n) {
dp[i].first = confidence[i];
}
for (int i = n-1; i >= 1; i--) {
if (protocol[i] == 0) {
dp[host[i]].first = dp[host[i]].first + dp[i].second;
dp[host[i]].second = max({
dp[host[i]].second + dp[i].second,
dp[host[i]].second + dp[i].first,
});
}
else if (protocol[i] == 1) {
dp[host[i]].first = max({
dp[host[i]].first + dp[i].first,
dp[host[i]].first + dp[i].second,
dp[host[i]].second + dp[i].first,
});
dp[host[i]].second = dp[host[i]].second + dp[i].second;
}
else if (protocol[i] == 2) {
dp[host[i]].first = max({
dp[host[i]].first + dp[i].second,
dp[host[i]].second + dp[i].first,
});
dp[host[i]].second = dp[host[i]].second + dp[i].second;
}
}
return max(dp[0].first, dp[0].second);
}
int main() {
int n; cin >> n;
int confidence[n], host[n], protocol[n];
REP(i, 0, n)
cin >> confidence[i];
host[0] = -1, protocol[0] = -1;
REP(i, 1, n)
cin >> host[i] >> protocol[i];
cout << findSample(n, confidence, host, protocol);
}