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Submission #967413

# Submission time Handle Problem Language Result Execution time Memory
967413 2024-04-22T05:14:11 Z steveonalex Beads and wires (APIO14_beads) C++17
100 / 100
 127 ms 27832 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define ALL(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
 
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng(1);
ll rngesus(ll l, ll r){return ((ull) rng()) % (r - l + 1) + l;}
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return mask & (-mask);}
ll pop_cnt(ll mask){return __builtin_popcountll(mask);}
ll ctz(ll mask){return __builtin_ctzll(mask);}
ll clz(ll mask){return __builtin_clzll(mask);}
ll logOf(ll mask){return 63 - clz(mask);}
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b){a = b; return true;}
        return false;
    }
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b){a = b; return true;}
        return false;
    }
template <class T>
    void printArr(T& a, string separator = " ", string finish = "\n", ostream& out = cout){
        for(auto i: a) out << i << separator;
        out << finish;
    }
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2e5 + 69;
const ll INF = 1e18 + 69;

int n;
vector<pair<int, int>> graph[N];
ll dp[N][2];
ll ans = 0;

void dfs(int u, int p){
    for(pair<int, int> v: graph[u]) if (v.first != p){
        dfs(v.first, u);
    }

    ll cu = 0;
    ll ma = -INF;
    for(pair<int, int> v: graph[u]) if (v.first != p){
        dp[u][0] += max(dp[v.first][1] + v.second, dp[v.first][0]);
        cu += max(dp[v.first][1] + v.second, dp[v.first][0]);
        maximize(ma, (v.second + dp[v.first][0]) - max(dp[v.first][1] + v.second, dp[v.first][0]));
    }
    if (ma > -INF){
        cu += ma;
        maximize(dp[u][1], cu);
    }
}

void go(int u, int p){
    maximize(ans, dp[u][0]);
    ll cu = 0;
    ll ma = -INF, secondMa = -INF;
    for(pair<int, int> v: graph[u]){
        cu += max(dp[v.first][1] + v.second, dp[v.first][0]);
        ll val = (v.second + dp[v.first][0]) - max(dp[v.first][1] + v.second, dp[v.first][0]);
        if (ma < val){
            secondMa = ma;
            ma = val;
        }
        else maximize(secondMa, val);
    }
    maximize(ans, cu + ma + secondMa);

    for(pair<int, int> v: graph[u]) if (v.first != p && graph[v.first].size() > 1){
        ll x1 = dp[u][0], x2 = dp[u][1];
        ll y1 = dp[v.first][0], y2 = dp[v.first][1];

        dp[u][0] -= max(dp[v.first][1] + v.second, dp[v.first][0]);
        dp[u][1] -= max(dp[v.first][1] + v.second, dp[v.first][0]);
        ll val = (v.second + dp[v.first][0]) - max(dp[v.first][1] + v.second, dp[v.first][0]);
        if (val == ma) dp[u][1] += secondMa - ma;

        dp[v.first][0] += max(dp[u][1] + v.second, dp[u][0]);
        dp[v.first][1] = 0;
        ll ma = -INF;
        for(pair<int, int> w: graph[v.first]) {
            dp[v.first][1] += max(dp[w.first][1] + w.second, dp[w.first][0]);
            maximize(ma, (w.second + dp[w.first][0]) - max(dp[w.first][1] + w.second, dp[w.first][0]));
        }
        dp[v.first][1] += ma;

        go(v.first, u);

        dp[u][0] = x1, dp[u][1] = x2;
        dp[v.first][0] = y1, dp[v.first][1] = y2;
    }
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n;
    for(int i = 1; i<n; ++i){
        int u, v, w; cin >> u >> v >> w;
        graph[u].push_back({v, w});
        graph[v].push_back({u, w});
    }

    if (n <= 2){cout << 0 << "\n"; return 0;}

    for(int i = 1; i<=n; ++i) sort(ALL(graph[i]));

    int root = -1;
    for(int i = 1; i<=n; ++i) if (graph[i].size() > 1) root = i;
    for(int i = 1; i<=n; ++i) {
        dp[i][0] = 0;
        dp[i][1] = -INF;
    }
    dfs(root, root);
    go(root,root);


    cout << ans << "\n";

    return 0;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5980 KB Output is correct
2 Correct 1 ms 5980 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 1 ms 5980 KB Output is correct
5 Correct 2 ms 6040 KB Output is correct
6 Correct 2 ms 5980 KB Output is correct
7 Correct 2 ms 5980 KB Output is correct
8 Correct 2 ms 5980 KB Output is correct
9 Correct 2 ms 5980 KB Output is correct
10 Correct 2 ms 5980 KB Output is correct
11 Correct 2 ms 5980 KB Output is correct
12 Correct 2 ms 5980 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5980 KB Output is correct
2 Correct 1 ms 5980 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 1 ms 5980 KB Output is correct
5 Correct 2 ms 6040 KB Output is correct
6 Correct 2 ms 5980 KB Output is correct
7 Correct 2 ms 5980 KB Output is correct
8 Correct 2 ms 5980 KB Output is correct
9 Correct 2 ms 5980 KB Output is correct
10 Correct 2 ms 5980 KB Output is correct
11 Correct 2 ms 5980 KB Output is correct
12 Correct 2 ms 5980 KB Output is correct
13 Correct 2 ms 5976 KB Output is correct
14 Correct 2 ms 5980 KB Output is correct
15 Correct 2 ms 5980 KB Output is correct
16 Correct 2 ms 5980 KB Output is correct
17 Correct 2 ms 5980 KB Output is correct
18 Correct 2 ms 5980 KB Output is correct
19 Correct 2 ms 5980 KB Output is correct
20 Correct 2 ms 5980 KB Output is correct
21 Correct 2 ms 5976 KB Output is correct
22 Correct 2 ms 5976 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5980 KB Output is correct
2 Correct 1 ms 5980 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 1 ms 5980 KB Output is correct
5 Correct 2 ms 6040 KB Output is correct
6 Correct 2 ms 5980 KB Output is correct
7 Correct 2 ms 5980 KB Output is correct
8 Correct 2 ms 5980 KB Output is correct
9 Correct 2 ms 5980 KB Output is correct
10 Correct 2 ms 5980 KB Output is correct
11 Correct 2 ms 5980 KB Output is correct
12 Correct 2 ms 5980 KB Output is correct
13 Correct 2 ms 5976 KB Output is correct
14 Correct 2 ms 5980 KB Output is correct
15 Correct 2 ms 5980 KB Output is correct
16 Correct 2 ms 5980 KB Output is correct
17 Correct 2 ms 5980 KB Output is correct
18 Correct 2 ms 5980 KB Output is correct
19 Correct 2 ms 5980 KB Output is correct
20 Correct 2 ms 5980 KB Output is correct
21 Correct 2 ms 5976 KB Output is correct
22 Correct 2 ms 5976 KB Output is correct
23 Correct 3 ms 6236 KB Output is correct
24 Correct 3 ms 6236 KB Output is correct
25 Correct 3 ms 6236 KB Output is correct
26 Correct 5 ms 6596 KB Output is correct
27 Correct 5 ms 6748 KB Output is correct
28 Correct 5 ms 6748 KB Output is correct
29 Correct 5 ms 6748 KB Output is correct
30 Correct 5 ms 6752 KB Output is correct
31 Correct 5 ms 7004 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 5980 KB Output is correct
2 Correct 1 ms 5980 KB Output is correct
3 Correct 2 ms 5980 KB Output is correct
4 Correct 1 ms 5980 KB Output is correct
5 Correct 2 ms 6040 KB Output is correct
6 Correct 2 ms 5980 KB Output is correct
7 Correct 2 ms 5980 KB Output is correct
8 Correct 2 ms 5980 KB Output is correct
9 Correct 2 ms 5980 KB Output is correct
10 Correct 2 ms 5980 KB Output is correct
11 Correct 2 ms 5980 KB Output is correct
12 Correct 2 ms 5980 KB Output is correct
13 Correct 2 ms 5976 KB Output is correct
14 Correct 2 ms 5980 KB Output is correct
15 Correct 2 ms 5980 KB Output is correct
16 Correct 2 ms 5980 KB Output is correct
17 Correct 2 ms 5980 KB Output is correct
18 Correct 2 ms 5980 KB Output is correct
19 Correct 2 ms 5980 KB Output is correct
20 Correct 2 ms 5980 KB Output is correct
21 Correct 2 ms 5976 KB Output is correct
22 Correct 2 ms 5976 KB Output is correct
23 Correct 3 ms 6236 KB Output is correct
24 Correct 3 ms 6236 KB Output is correct
25 Correct 3 ms 6236 KB Output is correct
26 Correct 5 ms 6596 KB Output is correct
27 Correct 5 ms 6748 KB Output is correct
28 Correct 5 ms 6748 KB Output is correct
29 Correct 5 ms 6748 KB Output is correct
30 Correct 5 ms 6752 KB Output is correct
31 Correct 5 ms 7004 KB Output is correct
32 Correct 20 ms 10844 KB Output is correct
33 Correct 21 ms 10844 KB Output is correct
34 Correct 20 ms 11096 KB Output is correct
35 Correct 127 ms 19024 KB Output is correct
36 Correct 108 ms 19028 KB Output is correct
37 Correct 126 ms 19508 KB Output is correct
38 Correct 78 ms 19432 KB Output is correct
39 Correct 79 ms 19512 KB Output is correct
40 Correct 91 ms 19444 KB Output is correct
41 Correct 114 ms 27832 KB Output is correct