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Submission #260577

# Submission time Handle Problem Language Result Execution time Memory
260577 2020-08-10T14:28:36 Z shayan_p Beads and wires (APIO14_beads) C++17
100 / 100
 282 ms 33656 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 = 2e5 + 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;
	
    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[j].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});
    }
    dfs(1);
    return cout << ans[1][1] << endl, 0;
}

Subtask #1
13.0 / 13.0

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

Subtask #2
15.0 / 15.0

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

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4992 KB Output is correct
2 Correct 3 ms 4992 KB Output is correct
3 Correct 3 ms 4992 KB Output is correct
4 Correct 3 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 3 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 3 ms 4992 KB Output is correct
10 Correct 3 ms 4992 KB Output is correct
11 Correct 3 ms 4992 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 3 ms 5120 KB Output is correct
15 Correct 4 ms 5120 KB Output is correct
16 Correct 4 ms 5120 KB Output is correct
17 Correct 4 ms 5120 KB Output is correct
18 Correct 3 ms 5120 KB Output is correct
19 Correct 4 ms 5120 KB Output is correct
20 Correct 3 ms 5120 KB Output is correct
21 Correct 5 ms 5120 KB Output is correct
22 Correct 3 ms 5120 KB Output is correct
23 Correct 7 ms 5364 KB Output is correct
24 Correct 7 ms 5376 KB Output is correct
25 Correct 7 ms 5376 KB Output is correct
26 Correct 10 ms 5760 KB Output is correct
27 Correct 10 ms 5888 KB Output is correct
28 Correct 11 ms 6448 KB Output is correct
29 Correct 10 ms 6056 KB Output is correct
30 Correct 11 ms 6144 KB Output is correct
31 Correct 11 ms 6784 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4992 KB Output is correct
2 Correct 3 ms 4992 KB Output is correct
3 Correct 3 ms 4992 KB Output is correct
4 Correct 3 ms 4992 KB Output is correct
5 Correct 4 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 3 ms 4992 KB Output is correct
8 Correct 4 ms 4992 KB Output is correct
9 Correct 3 ms 4992 KB Output is correct
10 Correct 3 ms 4992 KB Output is correct
11 Correct 3 ms 4992 KB Output is correct
12 Correct 4 ms 4992 KB Output is correct
13 Correct 4 ms 4992 KB Output is correct
14 Correct 3 ms 5120 KB Output is correct
15 Correct 4 ms 5120 KB Output is correct
16 Correct 4 ms 5120 KB Output is correct
17 Correct 4 ms 5120 KB Output is correct
18 Correct 3 ms 5120 KB Output is correct
19 Correct 4 ms 5120 KB Output is correct
20 Correct 3 ms 5120 KB Output is correct
21 Correct 5 ms 5120 KB Output is correct
22 Correct 3 ms 5120 KB Output is correct
23 Correct 7 ms 5364 KB Output is correct
24 Correct 7 ms 5376 KB Output is correct
25 Correct 7 ms 5376 KB Output is correct
26 Correct 10 ms 5760 KB Output is correct
27 Correct 10 ms 5888 KB Output is correct
28 Correct 11 ms 6448 KB Output is correct
29 Correct 10 ms 6056 KB Output is correct
30 Correct 11 ms 6144 KB Output is correct
31 Correct 11 ms 6784 KB Output is correct
32 Correct 43 ms 9284 KB Output is correct
33 Correct 56 ms 9336 KB Output is correct
34 Correct 57 ms 9208 KB Output is correct
35 Correct 282 ms 22392 KB Output is correct
36 Correct 251 ms 22392 KB Output is correct
37 Correct 251 ms 22264 KB Output is correct
38 Correct 229 ms 31840 KB Output is correct
39 Correct 236 ms 25828 KB Output is correct
40 Correct 238 ms 26024 KB Output is correct
41 Correct 271 ms 33656 KB Output is correct