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답안 #260570

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
260570 2020-08-10T14:23:08 Z shayan_p 구슬과 끈 (APIO14_beads) C++17
28 / 100
 1000 ms 1408 KB 
// And you curse yourself for things you never done

#include<bits/stdc++.h>

#define F first
#define S second
#define PB push_back
#define sz(s) int((s).size())
#define bit(n,k) (((n)>>(k))&1)

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;

const int maxn = 1e4 + 10, mod = 1e9 + 7; /////////
const ll inf = 1e18 + 10;

vector<pii> v[maxn];
ll ans[2][maxn], dp[2][maxn]; // 0 up 1 down

void dfs(int u, int par = -1){
    ll mx1 = -inf, mx2 = -inf;
    for(auto [y, c] : v[u]){
	if(y != par){
	    dfs(y, u);
	    ll x = max(ans[0][y], dp[0][y] + c);
	    ans[0][u]+= x;
	    dp[0][u]+= x;
	    mx1 = max(mx1, c + ans[0][y] - x);

	    dp[1][u]+= x;
	    mx2 = max(mx2, c + ans[1][y] - x);
	}
    }
    dp[0][u]+= mx1;
    dp[1][u]+= mx2;

    return;/////
	
    ll sm = 0;
    ll mx = -inf;

    vector<pair<ll, int> > v1, v2;
    for(auto [y, c] : v[u]){
	if(y != par){
	    ll x = max(ans[0][y], dp[0][y] + c);
	    sm+= x;
	    mx = max(mx, max(dp[1][y] + c, ans[1][y]) -x);
	    v1.PB({ans[1][y] + c - x, y});
	    v2.PB({ans[0][y] + c - x, y});
	}
    }
    sort(v1.begin(), v1.end());
    reverse(v1.begin(), v1.end());
    sort(v2.begin(), v2.end());
    reverse(v2.begin(), v2.end());
    for(int i = 0; i < min(2, sz(v1)); i++)
	for(int j = 0; j < min(2, sz(v2)); j++)
	    if(v1[i].S != v2[j].S)
		ans[1][u] = max(ans[1][u], sm + v1[i].F + v2[i].F);
    ans[1][u] = max(ans[1][u], sm + mx);
    ans[1][u] = max(ans[1][u], ans[0][u]);
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie();

    int n;
    cin >> n;
    for(int i = 0; i < n-1; i++){
	int a, b, c;
	cin >> a >> b >> c;
	v[a].PB({b, c});
	v[b].PB({a, c});
    }

    ll ANS = 0;
    for(int u = 1; u <= n; u++){
	memset(ans, 0, sizeof ans);
	memset(dp, 0, sizeof dp);
	dfs(u);
	ANS = max(ANS, ans[0][u]);
    }
    return cout << ANS << endl, 0;
}

Subtask #1
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 896 KB Output is correct
2 Correct 1 ms 896 KB Output is correct
3 Correct 1 ms 896 KB Output is correct
4 Correct 1 ms 896 KB Output is correct
5 Correct 1 ms 896 KB Output is correct
6 Correct 1 ms 896 KB Output is correct
7 Correct 1 ms 896 KB Output is correct
8 Correct 1 ms 896 KB Output is correct
9 Correct 1 ms 896 KB Output is correct
10 Correct 1 ms 896 KB Output is correct
11 Correct 1 ms 896 KB Output is correct
12 Correct 1 ms 896 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 896 KB Output is correct
2 Correct 1 ms 896 KB Output is correct
3 Correct 1 ms 896 KB Output is correct
4 Correct 1 ms 896 KB Output is correct
5 Correct 1 ms 896 KB Output is correct
6 Correct 1 ms 896 KB Output is correct
7 Correct 1 ms 896 KB Output is correct
8 Correct 1 ms 896 KB Output is correct
9 Correct 1 ms 896 KB Output is correct
10 Correct 1 ms 896 KB Output is correct
11 Correct 1 ms 896 KB Output is correct
12 Correct 1 ms 896 KB Output is correct
13 Correct 2 ms 896 KB Output is correct
14 Correct 2 ms 928 KB Output is correct
15 Correct 2 ms 896 KB Output is correct
16 Correct 4 ms 896 KB Output is correct
17 Correct 4 ms 896 KB Output is correct
18 Correct 3 ms 896 KB Output is correct
19 Correct 4 ms 896 KB Output is correct
20 Correct 4 ms 896 KB Output is correct
21 Correct 4 ms 896 KB Output is correct
22 Correct 4 ms 896 KB Output is correct

Subtask #3
0 / 29.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 896 KB Output is correct
2 Correct 1 ms 896 KB Output is correct
3 Correct 1 ms 896 KB Output is correct
4 Correct 1 ms 896 KB Output is correct
5 Correct 1 ms 896 KB Output is correct
6 Correct 1 ms 896 KB Output is correct
7 Correct 1 ms 896 KB Output is correct
8 Correct 1 ms 896 KB Output is correct
9 Correct 1 ms 896 KB Output is correct
10 Correct 1 ms 896 KB Output is correct
11 Correct 1 ms 896 KB Output is correct
12 Correct 1 ms 896 KB Output is correct
13 Correct 2 ms 896 KB Output is correct
14 Correct 2 ms 928 KB Output is correct
15 Correct 2 ms 896 KB Output is correct
16 Correct 4 ms 896 KB Output is correct
17 Correct 4 ms 896 KB Output is correct
18 Correct 3 ms 896 KB Output is correct
19 Correct 4 ms 896 KB Output is correct
20 Correct 4 ms 896 KB Output is correct
21 Correct 4 ms 896 KB Output is correct
22 Correct 4 ms 896 KB Output is correct
23 Correct 774 ms 1272 KB Output is correct
24 Correct 758 ms 1272 KB Output is correct
25 Correct 733 ms 1192 KB Output is correct
26 Execution timed out 1096 ms 1408 KB Time limit exceeded
27 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 896 KB Output is correct
2 Correct 1 ms 896 KB Output is correct
3 Correct 1 ms 896 KB Output is correct
4 Correct 1 ms 896 KB Output is correct
5 Correct 1 ms 896 KB Output is correct
6 Correct 1 ms 896 KB Output is correct
7 Correct 1 ms 896 KB Output is correct
8 Correct 1 ms 896 KB Output is correct
9 Correct 1 ms 896 KB Output is correct
10 Correct 1 ms 896 KB Output is correct
11 Correct 1 ms 896 KB Output is correct
12 Correct 1 ms 896 KB Output is correct
13 Correct 2 ms 896 KB Output is correct
14 Correct 2 ms 928 KB Output is correct
15 Correct 2 ms 896 KB Output is correct
16 Correct 4 ms 896 KB Output is correct
17 Correct 4 ms 896 KB Output is correct
18 Correct 3 ms 896 KB Output is correct
19 Correct 4 ms 896 KB Output is correct
20 Correct 4 ms 896 KB Output is correct
21 Correct 4 ms 896 KB Output is correct
22 Correct 4 ms 896 KB Output is correct
23 Correct 774 ms 1272 KB Output is correct
24 Correct 758 ms 1272 KB Output is correct
25 Correct 733 ms 1192 KB Output is correct
26 Execution timed out 1096 ms 1408 KB Time limit exceeded
27 Halted 0 ms 0 KB -