oj.uz

Submission #39303

# Submission time Handle Problem Language Result Execution time Memory
39303 2018-01-11T05:29:25 Z qoo2p5 Beads and wires (APIO14_beads) C++14
100 / 100
 399 ms 25580 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;
const ld EPS = (ld) 1e-7;
const ll MOD = (ll) 1e9 + 7;

#define sz(x) (int) (x).size()
#define mp(x, y) make_pair(x, y)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lb(s, t, x) (int) (lower_bound(s, t, x) - s)
#define ub(s, t, x) (int) (upper_bound(s, t, x) - s)
#define rep(i, f, t) for (int i = f; i < t; i++)
#define per(i, f, t) for (int i = f; i >= t; i--)

ll power(ll x, ll y, ll mod = MOD) {
    if (y == 0) {
        return 1;
    }
    if (y & 1) {
        return power(x, y - 1, mod) * x % mod;
    } else {
        ll tmp = power(x, y / 2, mod);
        return tmp * tmp % mod;
    }
}

template<typename A, typename B> bool mini(A &x, const B &y) {
    if (y < x) {
        x = y;
        return true;
    }
    return false;
}

template<typename A, typename B> bool maxi(A &x, const B &y) {
    if (y > x) {
        x = y;
        return true;
    }
    return false;
}

void add(ll &x, ll y) {
	x += y;
	if (x >= MOD) x -= MOD;
	if (x < 0) x += MOD;
}

ll mult(ll x, ll y) {
	return x * y % MOD;
}

void run();

#define TASK ""

int main() {
#ifdef LOCAL
    if (strlen(TASK) > 0) {
        cerr << "Reminder: you are using file i/o, filename: " TASK "!" << endl << endl;
    }
#endif
#ifndef LOCAL
    if (strlen(TASK)) {
        freopen(TASK ".in", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
#endif
    cout << fixed << setprecision(12);
    run();
    return 0;
}

// == SOLUTION == //

const int N = (int) 2e5 + 123;

int n;
vector<pair<int, int>> g[N];
int take[N], ntake[N];
ll ans;

void dfs1(int v, int f = -1, int up_w = 0) {
	ntake[v] = 0;
	take[v] = 0;
	
	rep(i, 0, sz(g[v])) {
		int u = g[v][i].first;
		if (u == f) {
			continue;
		}
		dfs1(u, v, g[v][i].second);
		ntake[v] += take[u];
	}
	
	if (f != -1) {
		for (auto &it : g[v]) {
			int u = it.first;
			if (u == f) {
				continue;
			}
			maxi(take[v], ntake[v] - take[u] + ntake[u] + it.second + up_w);
		}
	}
	
	maxi(take[v], ntake[v]);
}

void dfs2(int v, int f = -1, int up = 0, int prv_up = 0, int up_w = 0) {
	multiset<int> q;
	for (auto &it : g[v]) {
		int u = it.first;
		if (u == f) {
			continue;
		}
		q.insert(-take[u] + ntake[u] + it.second);
	}
	for (auto &it : g[v]) {
		int u = it.first;
		if (u == f) {
			continue;
		}
		
		q.erase(q.find(-take[u] + ntake[u] + it.second));
		
		int nup = up + ntake[v] - take[u];
		if (f != -1) {
			maxi(nup, ntake[v] - take[u] + prv_up + ntake[f] - take[v] + it.second + up_w);
		}
		if (sz(q)) maxi(nup, ntake[v] - take[u] + up + *q.rbegin() + it.second);
		dfs2(u, v, nup, up, it.second);
		
		q.insert(-take[u] + ntake[u] + it.second);
	}
	
	maxi(ans, ntake[v] + up);
}

void run() {
	cin >> n;
	rep(i, 1, n) {
		int u, v, c;
		cin >> u >> v >> c;
		g[u].pb({v, c});
		g[v].pb({u, c});
	}
	
	dfs1(1);
	ans = ntake[1];
	dfs2(1);
	
	cout << ans << "\n";
}

Compilation message

beads.cpp: In function 'int main()':
beads.cpp:72:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(TASK ".in", "r", stdin);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         freopen(TASK ".out", "w", stdout);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 5084 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 5084 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 5 ms 4992 KB Output is correct
19 Correct 5 ms 5024 KB Output is correct
20 Correct 5 ms 4992 KB Output is correct
21 Correct 5 ms 4992 KB Output is correct
22 Correct 5 ms 4992 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 5084 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 5 ms 4992 KB Output is correct
19 Correct 5 ms 5024 KB Output is correct
20 Correct 5 ms 4992 KB Output is correct
21 Correct 5 ms 4992 KB Output is correct
22 Correct 5 ms 4992 KB Output is correct
23 Correct 8 ms 5248 KB Output is correct
24 Correct 9 ms 5248 KB Output is correct
25 Correct 9 ms 5248 KB Output is correct
26 Correct 12 ms 5536 KB Output is correct
27 Correct 12 ms 5476 KB Output is correct
28 Correct 15 ms 5988 KB Output is correct
29 Correct 15 ms 5888 KB Output is correct
30 Correct 14 ms 5760 KB Output is correct
31 Correct 14 ms 6400 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 5 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 5 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 5 ms 5120 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 5 ms 4992 KB Output is correct
11 Correct 5 ms 4992 KB Output is correct
12 Correct 6 ms 5084 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 5 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 5 ms 4992 KB Output is correct
18 Correct 5 ms 4992 KB Output is correct
19 Correct 5 ms 5024 KB Output is correct
20 Correct 5 ms 4992 KB Output is correct
21 Correct 5 ms 4992 KB Output is correct
22 Correct 5 ms 4992 KB Output is correct
23 Correct 8 ms 5248 KB Output is correct
24 Correct 9 ms 5248 KB Output is correct
25 Correct 9 ms 5248 KB Output is correct
26 Correct 12 ms 5536 KB Output is correct
27 Correct 12 ms 5476 KB Output is correct
28 Correct 15 ms 5988 KB Output is correct
29 Correct 15 ms 5888 KB Output is correct
30 Correct 14 ms 5760 KB Output is correct
31 Correct 14 ms 6400 KB Output is correct
32 Correct 46 ms 7292 KB Output is correct
33 Correct 45 ms 7288 KB Output is correct
34 Correct 44 ms 7296 KB Output is correct
35 Correct 273 ms 14028 KB Output is correct
36 Correct 274 ms 14108 KB Output is correct
37 Correct 255 ms 14072 KB Output is correct
38 Correct 399 ms 22844 KB Output is correct
39 Correct 376 ms 24024 KB Output is correct
40 Correct 356 ms 22752 KB Output is correct
41 Correct 348 ms 25580 KB Output is correct