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Submission #31630

# Submission time Handle Problem Language Result Execution time Memory
31630 2017-08-30T04:30:28 Z aome Beads and wires (APIO14_beads) C++14
100 / 100
 247 ms 22380 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;

typedef pair<int, int> ii;
const int N = 200005;
const int INF = -1e9;

int n, res;
int f[N][2], g[N][2];
int L[N], R[N];
vector<ii> G[N];

void dfs(int u, int p) {
    for (auto v : G[u]) {
        if (v.fi == p) continue;
        dfs(v.fi, u);
    }
    int mx = INF;
    for (auto v : G[u]) {
        if (v.fi == p) continue;
        int vMx = max(f[v.fi][0], f[v.fi][1] + v.se);
        f[u][0] += vMx;
        mx = max(mx, f[v.fi][0] + v.se - vMx);
    }
    f[u][1] = f[u][0] + mx;
}

void reDfs(int u, int p) {
    vector<ii> _G;
    for (auto v : G[u]) {
        if (v.fi == p) continue;
        _G.push_back(v);
    }
    int sz = _G.size(), sum = 0;
    L[0] = INF, R[sz + 1] = INF;
    for (int i = 1; i <= sz; ++i) {
        ii v = _G[i - 1];
        sum += max(f[v.fi][0], f[v.fi][1] + v.se);
        int vMx = max(f[v.fi][0], f[v.fi][1] + v.se);
        L[i] = max(L[i - 1], f[v.fi][0] + v.se - vMx);
    }
    for (int i = sz; i >= 1; --i) {
        ii v = _G[i - 1];
        int vMx = max(f[v.fi][0], f[v.fi][1] + v.se);
        R[i] = max(R[i + 1], f[v.fi][0] + v.se - vMx);
    }
    for (int i = 1; i <= sz; ++i) {
        ii v = _G[i - 1];
        int mx = max(L[i - 1], R[i + 1]);
        int tSum = sum - max(f[v.fi][0], f[v.fi][1] + v.se);
        tSum += g[u][0], mx = max(mx, g[u][1] - g[u][0]);
        // f0 = tSum, f1 = tSum + mx;
        g[v.fi][0] = max(tSum, tSum + mx + v.second), g[v.fi][1] = tSum + v.second;
    }
    //cout << u << ' ' << f[u][0] << ' ' << f[u][1] << '\n';
    //cout << u << ' ' << g[u][0] << ' ' << g[u][1] << '\n';
    res = max(res, f[u][0] + g[u][0]);
    for (auto v : _G) reDfs(v.fi, u);
}

int main() {
    ios::sync_with_stdio(false);
    cin >> n;
    for (int i = 1; i < n; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        G[u].push_back(ii(v, w));
        G[v].push_back(ii(u, w));
    }
    dfs(1, 1);
    g[1][1] = INF;
    res = f[1][0];
    reDfs(1, 1);
    cout << res;
//    int res = 0;
//    for (int i = 1; i <= n; ++i) {
//        dfs(i, i), res = max(res, f[i][0]);
//    }
//    cout << res;
}

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 7 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 6 ms 5120 KB Output is correct

Subtask #2
15.0 / 15.0

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

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 7 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 6 ms 5120 KB Output is correct
13 Correct 5 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 6 ms 5120 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 4992 KB Output is correct
19 Correct 5 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 5120 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 8 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 8 ms 5248 KB Output is correct
26 Correct 11 ms 5632 KB Output is correct
27 Correct 11 ms 5632 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 10 ms 5760 KB Output is correct
30 Correct 10 ms 5760 KB Output is correct
31 Correct 11 ms 6144 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 5120 KB Output is correct
2 Correct 6 ms 5120 KB Output is correct
3 Correct 5 ms 4992 KB Output is correct
4 Correct 7 ms 5120 KB Output is correct
5 Correct 6 ms 5120 KB Output is correct
6 Correct 6 ms 5120 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 5120 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 6 ms 4992 KB Output is correct
11 Correct 6 ms 5120 KB Output is correct
12 Correct 6 ms 5120 KB Output is correct
13 Correct 5 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 6 ms 5120 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 4992 KB Output is correct
19 Correct 5 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 5120 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 8 ms 5376 KB Output is correct
24 Correct 9 ms 5376 KB Output is correct
25 Correct 8 ms 5248 KB Output is correct
26 Correct 11 ms 5632 KB Output is correct
27 Correct 11 ms 5632 KB Output is correct
28 Correct 11 ms 5888 KB Output is correct
29 Correct 10 ms 5760 KB Output is correct
30 Correct 10 ms 5760 KB Output is correct
31 Correct 11 ms 6144 KB Output is correct
32 Correct 35 ms 7672 KB Output is correct
33 Correct 38 ms 7672 KB Output is correct
34 Correct 36 ms 7800 KB Output is correct
35 Correct 247 ms 15692 KB Output is correct
36 Correct 242 ms 15608 KB Output is correct
37 Correct 240 ms 15608 KB Output is correct
38 Correct 150 ms 18888 KB Output is correct
39 Correct 129 ms 18884 KB Output is correct
40 Correct 147 ms 18084 KB Output is correct
41 Correct 216 ms 22380 KB Output is correct