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Submission #123452

# Submission time Handle Problem Language Result Execution time Memory
123452 2019-07-01T13:04:39 Z popovicirobert Beads and wires (APIO14_beads) C++14
100 / 100
 291 ms 26984 KB 
#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
// 217
// 44


/*const int MOD = ;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}


inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}*/


using namespace std;

const ll INF = 1e10;
const int MAXN = (int) 2e5;

vector < pair <int, int> > g[MAXN + 1];
ll dp[MAXN + 1][2], cst[MAXN + 1];
// dp[nod][0] = nu ai spart nimic
// dp[nod][1] = ai spart un fiu de tata

void dfs(int nod, int par) {
    vector <ll> cur(2, -INF);
    cur[0] = 0;

    for(auto it : g[nod]) {
        if(it.first != par) {
            cst[it.first] = it.second;
            dfs(it.first, nod);

            ll mx = max(dp[it.first][1] + it.second, dp[it.first][0]);
            cur[1] = max(cur[0] + dp[it.first][0] + it.second, cur[1] + mx);
            cur[0] += mx;
        }
    }
    dp[nod][0] = cur[0], dp[nod][1] = cur[1];
}

ll ans;

void solve(int nod, int par) {
    ans = max(ans, dp[nod][0]);

    vector < pair <ll, int> > vals;
    for(auto it : g[nod]) {
        vals.push_back({dp[it.first][0] + it.second - max(dp[it.first][0], dp[it.first][1] + it.second), it.first});
    }
    sort(vals.begin(), vals.end(), greater < pair <ll, int> >());

    for(auto it : g[nod]) {
        if(it.first != par) {
            ll a = dp[nod][0], b = dp[nod][1], c = dp[it.first][0], d = dp[it.first][1];
            ll mx = max(dp[it.first][0], dp[it.first][1] + it.second);

            dp[nod][0] -= mx;
            if(it.first != vals[0].second) {
                dp[nod][1] -= mx;
            }
            else {
                if(vals.size() > 1) {
                    dp[nod][1] -= dp[it.first][0] + it.second;
                    dp[nod][1] += vals[1].first;
                }
                else {
                    dp[nod][1] = -INF;
                }
            }

            mx = max(dp[nod][0], dp[nod][1] + it.second);
            dp[it.first][1] = max(dp[it.first][1] + mx, dp[it.first][0] + dp[nod][0] + it.second);
            dp[it.first][0] += mx;

            solve(it.first, nod);

            dp[nod][0] = a, dp[nod][1] = b, dp[it.first][0] = c, dp[it.first][1] = d;
        }
    }
}

int main() {
    //ifstream cin("A.in");
    //ofstream cout("A.out");
    int i, n;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n;

    for(i = 1; i < n; i++) {
        int x, y, z;
        cin >> x >> y >> z;
        g[x].push_back({y, z});
        g[y].push_back({x, z});
    }

    dfs(1, 0);
    solve(1, 0);

    cout << ans;

    //cin.close();
    //cout.close();
    return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4988 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 5160 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4968 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4988 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 5160 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4968 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 6 ms 5032 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 6 ms 4984 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 4984 KB Output is correct
2 Correct 6 ms 4988 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 5160 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4968 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 6 ms 5032 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 6 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5496 KB Output is correct
24 Correct 9 ms 5368 KB Output is correct
25 Correct 10 ms 5496 KB Output is correct
26 Correct 14 ms 5880 KB Output is correct
27 Correct 13 ms 5752 KB Output is correct
28 Correct 13 ms 6264 KB Output is correct
29 Correct 13 ms 6008 KB Output is correct
30 Correct 13 ms 6008 KB Output is correct
31 Correct 14 ms 6648 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4988 KB Output is correct
3 Correct 6 ms 5112 KB Output is correct
4 Correct 6 ms 4984 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 5160 KB Output is correct
7 Correct 6 ms 4984 KB Output is correct
8 Correct 6 ms 5112 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4968 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 6 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 5112 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 6 ms 5032 KB Output is correct
19 Correct 6 ms 5112 KB Output is correct
20 Correct 6 ms 4984 KB Output is correct
21 Correct 6 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 10 ms 5496 KB Output is correct
24 Correct 9 ms 5368 KB Output is correct
25 Correct 10 ms 5496 KB Output is correct
26 Correct 14 ms 5880 KB Output is correct
27 Correct 13 ms 5752 KB Output is correct
28 Correct 13 ms 6264 KB Output is correct
29 Correct 13 ms 6008 KB Output is correct
30 Correct 13 ms 6008 KB Output is correct
31 Correct 14 ms 6648 KB Output is correct
32 Correct 45 ms 8312 KB Output is correct
33 Correct 45 ms 8284 KB Output is correct
34 Correct 45 ms 8312 KB Output is correct
35 Correct 267 ms 17400 KB Output is correct
36 Correct 250 ms 17544 KB Output is correct
37 Correct 287 ms 17624 KB Output is correct
38 Correct 206 ms 21984 KB Output is correct
39 Correct 233 ms 22116 KB Output is correct
40 Correct 242 ms 21096 KB Output is correct
41 Correct 291 ms 26984 KB Output is correct