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Submission #124151

# Submission time Handle Problem Language Result Execution time Memory
124151 2019-07-02T15:06:08 Z youngyojun Beads and wires (APIO14_beads) C++11
100 / 100
 294 ms 33008 KB 
#include <bits/stdc++.h>
#define eb emplace_back
#define INFLL (0x3f3f3f3f3f3f3f3fll)
using namespace std;
typedef long long ll;

const int MAXN = 200055;

ll D[MAXN*2], E[MAXN*2];
ll MX[MAXN][2];
ll S[MAXN];

int O[MAXN*2];
bitset<MAXN*2> chk;

vector<int> G[MAXN];
int cnt[MAXN];
int A[MAXN], B[MAXN], C[MAXN];

ll Ans;
int N;

int getC(int e) { return (e&1) ? N-cnt[B[e>>1]] : cnt[B[e>>1]]; }

void dfs(int i) {
	cnt[i] = 1;
	for(int e : G[i]) {
		int v = A[e]^B[e]^i;
		if(cnt[v]) continue;
		dfs(v);
		cnt[i] += cnt[v];
	}
}

int main() {
	ios::sync_with_stdio(false);

	cin >> N;
	for(int i = 0; i < N-1; i++) {
		cin >> A[i] >> B[i] >> C[i];
		G[A[i]].eb(i);
		G[B[i]].eb(i);
	}

	dfs(1);
	for(int i = 0; i < N-1; i++)
		if(cnt[A[i]] < cnt[B[i]]) swap(A[i], B[i]);
	
	fill(MX[0], MX[N]+2, -INFLL);
	
	iota(O, O+(N-1)*2, 0); sort(O, O+(N-1)*2, [&](int a, int b) {
		return getC(a) < getC(b);
	});
	for(int oi = 0, e, v, p; oi < (N-1)*2; oi++) {
		e = O[oi]; v = B[e>>1]; p = A[e>>1];
		if(e&1) swap(v, p);
		chk[e] = true;
		D[e] = S[v] - (chk[e^1] ? max(D[e^1], E[e^1]) : 0);
		if(chk[e^1]) {
			ll t = -max(D[e^1], E[e^1]) + D[e^1] + C[e>>1];
			E[e] = MX[v][0] == t ? MX[v][1] : MX[v][0];
		} else E[e] = MX[v][0];
		E[e] += D[e] + C[e>>1];

		S[p] += max(D[e], E[e]);
		{
			ll t = -max(D[e], E[e]) + D[e] + C[e>>1];
			if(MX[p][0] < t) swap(MX[p][0], t);
			if(MX[p][1] < t) swap(MX[p][1], t);
		}
	}

	for(int i = 1; i <= N; i++) {
		ll sum = 0;
		for(int e : G[i]) {
			int v = A[e]^B[e]^i;
			e = (e<<1) | (B[e] == i ? 1 : 0);
			sum += max(D[e], E[e]);
		}
		if(Ans < sum) Ans = sum;
	}

	cout << Ans << endl;
	return 0;
}

Compilation message

beads.cpp: In function 'int main()':
beads.cpp:76:8: warning: unused variable 'v' [-Wunused-variable]
    int v = A[e]^B[e]^i;
        ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 5084 KB Output is correct
5 Correct 6 ms 5068 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 5084 KB Output is correct
5 Correct 6 ms 5068 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5084 KB Output is correct
18 Correct 6 ms 5112 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 6 ms 5112 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 5084 KB Output is correct
5 Correct 6 ms 5068 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5084 KB Output is correct
18 Correct 6 ms 5112 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 6 ms 5112 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5756 KB Output is correct
24 Correct 12 ms 5752 KB Output is correct
25 Correct 10 ms 5760 KB Output is correct
26 Correct 14 ms 6392 KB Output is correct
27 Correct 14 ms 6392 KB Output is correct
28 Correct 13 ms 6392 KB Output is correct
29 Correct 13 ms 6384 KB Output is correct
30 Correct 13 ms 6420 KB Output is correct
31 Correct 15 ms 6520 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5112 KB Output is correct
2 Correct 6 ms 5112 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 5084 KB Output is correct
5 Correct 6 ms 5068 KB Output is correct
6 Correct 6 ms 5112 KB Output is correct
7 Correct 6 ms 5112 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 5112 KB Output is correct
10 Correct 6 ms 5112 KB Output is correct
11 Correct 6 ms 5112 KB Output is correct
12 Correct 6 ms 5112 KB Output is correct
13 Correct 6 ms 5112 KB Output is correct
14 Correct 6 ms 5112 KB Output is correct
15 Correct 6 ms 5112 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5084 KB Output is correct
18 Correct 6 ms 5112 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 6 ms 5112 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5756 KB Output is correct
24 Correct 12 ms 5752 KB Output is correct
25 Correct 10 ms 5760 KB Output is correct
26 Correct 14 ms 6392 KB Output is correct
27 Correct 14 ms 6392 KB Output is correct
28 Correct 13 ms 6392 KB Output is correct
29 Correct 13 ms 6384 KB Output is correct
30 Correct 13 ms 6420 KB Output is correct
31 Correct 15 ms 6520 KB Output is correct
32 Correct 58 ms 11344 KB Output is correct
33 Correct 57 ms 11384 KB Output is correct
34 Correct 56 ms 11432 KB Output is correct
35 Correct 269 ms 30704 KB Output is correct
36 Correct 280 ms 30812 KB Output is correct
37 Correct 281 ms 30720 KB Output is correct
38 Correct 206 ms 31336 KB Output is correct
39 Correct 200 ms 31332 KB Output is correct
40 Correct 214 ms 31312 KB Output is correct
41 Correct 294 ms 33008 KB Output is correct