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답안 #412625

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
412625 2021-05-27T08:15:10 Z LastRonin 구슬과 끈 (APIO14_beads) C++14
0 / 100
 9 ms 12040 KB 
#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define ll long long
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define pill pair<ll, ll>
using namespace std;
const ll N = 5e5 + 10;
const ll big = 1e16;

ll n;
vector<pill> g[N];
ll dp[N][2], dp2[2][3], dp3[2][2];

void dfs(ll v, ll p, ll z) {	
	for(auto u : g[v]) {
		if(u.f != p)
			dfs(u.f, v, u.s);
	}
	dp2[0][0] = 0, dp2[0][1] = -big, dp2[0][2] = -big;
	for(auto u : g[v]) {	
		if(u.f == p)continue;
		dp2[1][0] = dp2[0][0] + max(dp[u.f][0], dp[u.f][1]);
		dp2[1][1] = max(dp2[0][1] + max(dp[u.f][0], dp[u.f][1]), dp2[0][0] + dp[u.f][0] + u.s);
		dp2[1][2] = max(dp2[0][2] + max(dp[u.f][0], dp[u.f][1]), dp2[0][1] + dp[u.f][0] + u.s);  
		dp2[0][0] = dp2[1][0];
		dp2[0][1] = dp2[1][1];
		dp2[0][2] = dp2[1][2];	
	}
	dp3[0][0] = 0, dp3[0][1] = -big;                           
	for(auto u : g[v]) {
		if(u.f == p)continue;
		dp3[1][0] = dp3[0][0] + max(dp[u.f][1], dp[u.f][0]);
		dp3[1][1] = max(dp3[0][1] + max(dp[u.f][1], dp[u.f][0]), dp3[0][0] + u.s + dp[u.f][0]);
		dp3[0][0] = dp3[1][0];
		dp3[0][1] = dp3[1][1];
	}
	dp[v][0] = max(dp2[0][0], dp2[0][2]);
	dp[v][1] = dp3[0][1] + z;
}

int main() {
	speed;
	cin >> n;
	for(int i = 1, a, b, c; i < n; i++)
		cin >> a >> b >> c, g[a].pb(mp(b, c)), g[b].pb(mp(a, c));
	dfs(2, 0, 0);
	cout << dp[2][0]; 
}
/*
10
4 10 2
1 2 21
1 3 13
6 7 1
7 9 5
2 4 3
2 5 8
1 6 55
6 8 34

*/

Subtask #1
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 12040 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 7 ms 11976 KB Output is correct
4 Correct 7 ms 12004 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Incorrect 9 ms 11956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 12040 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 7 ms 11976 KB Output is correct
4 Correct 7 ms 12004 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Incorrect 9 ms 11956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 12040 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 7 ms 11976 KB Output is correct
4 Correct 7 ms 12004 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Incorrect 9 ms 11956 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Correct 7 ms 12040 KB Output is correct
2 Correct 7 ms 11980 KB Output is correct
3 Correct 7 ms 11976 KB Output is correct
4 Correct 7 ms 12004 KB Output is correct
5 Correct 7 ms 11980 KB Output is correct
6 Incorrect 9 ms 11956 KB Output isn't correct
7 Halted 0 ms 0 KB -