oj.uz

Submission #720246

# Submission time Handle Problem Language Result Execution time Memory
720246 2023-04-07T18:00:47 Z jcelin Islands (IOI08_islands) C++14
90 / 100
 624 ms 131072 KB 
#include <bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;

#define ii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vii vector<ii>
#define vll vector<ll>
#define vpll vector<pll>
#define msi multiset<int>
#define si set<int>
#define PB push_back
#define PF push_front
#define PPB pop_back
#define PPF pop_front
#define X first
#define Y second
#define MP make_pair
#define FOR(i, a, b) for (int i = int(a); i < int(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define all(x) (x).begin(), (x).end()

const int mod = 1e9 + 7;
const int MOD = 998244353;
const int inf = mod;
const ll INF = 1e18;
const int logo = 20;
const int MAXN = 1e6 + 7;
const int off = 1 << logo;
const int trsz = off << 1;

bool bio[MAXN];
ll to[MAXN], w[MAXN]; 
vi g[MAXN];
ll ans, ret;
vll dp, s;

int ciklus(int u){
	if(bio[u]) return u;
	bio[u] = 1;
	int v = ciklus(to[u]);
	if(v){
		dp.PB(u);
		s.PB(w[u]);
		if(u == v) return 0;
		return v;
	}
	bio[u] = 0;
	return 0;
}

ll dfs(int u){
	ll mx = 0;
	bio[u] = 1;
	for(int x : g[u]){
		if(bio[x]) continue;
		ll ch = (ll)w[x] + dfs(x);
		ret = max(ret, (ll)ch + (ll)mx);
		mx = max(mx, ch);
	}
	return mx;
}

void resi(int u){
	dp.clear(), s.clear();
	ciklus(u);
	int sz = s.size();
	reverse(all(dp));
	reverse(all(s));
	for(ll &x : dp) x = (ll)dfs(x);
	for(int i = sz - 1; i; i--) swap(s[i], s[i - 1]);
	FOR(i, 1, sz) s[i] += s[i - 1];
	ll m1 = -INF, m2 = -INF;
	REP(i, sz){
		ret = max(ret, (ll)dp[i] + (ll)s[i] + (ll)m1);
		ret = max(ret, (ll)s[sz - 1] + (ll)m2 + (ll)dp[i] - (ll)s[i]);
		m1 = max(m1, (ll)dp[i] - (ll)s[i]);
		m2 = max(m2, (ll)dp[i] + (ll)s[i]);
	}
}

void solve(){
	int n;
	cin >> n;
	FOR(i, 1, n + 1) cin >> to[i] >> w[i], g[to[i]].PB(i); 
	FOR(i, 1, n + 1) if(!bio[i]) ret = 0, resi(i), ans += ret;
	cout << ans << "\n";
}


int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int t=1;
	//cin >> t;
	while(t--)solve();
	return 0;
}

Subtask #1
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 23764 KB Output is correct
2 Correct 15 ms 23764 KB Output is correct
3 Correct 16 ms 23784 KB Output is correct
4 Correct 14 ms 23736 KB Output is correct
5 Correct 13 ms 23732 KB Output is correct
6 Correct 13 ms 23764 KB Output is correct
7 Correct 13 ms 23792 KB Output is correct
8 Correct 13 ms 23836 KB Output is correct
9 Correct 13 ms 23736 KB Output is correct
10 Correct 13 ms 23740 KB Output is correct
11 Correct 14 ms 23764 KB Output is correct

Subtask #2
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 23860 KB Output is correct
2 Correct 13 ms 23844 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 23892 KB Output is correct
2 Correct 16 ms 24104 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 24588 KB Output is correct
2 Correct 25 ms 26628 KB Output is correct
3 Correct 19 ms 24780 KB Output is correct
4 Correct 17 ms 24320 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 27184 KB Output is correct
2 Correct 36 ms 29160 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 61 ms 32396 KB Output is correct
2 Correct 67 ms 40420 KB Output is correct
3 Correct 95 ms 45224 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 102 ms 40268 KB Output is correct
2 Correct 129 ms 55736 KB Output is correct
3 Correct 146 ms 72716 KB Output is correct
4 Correct 207 ms 77280 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 209 ms 44480 KB Output is correct
2 Correct 443 ms 95956 KB Output is correct
3 Correct 220 ms 53080 KB Output is correct
4 Correct 255 ms 82972 KB Output is correct
5 Correct 305 ms 80792 KB Output is correct
6 Correct 624 ms 74028 KB Output is correct
7 Correct 365 ms 123428 KB Output is correct

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 264 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -