oj.uz

Submission #558040

# Submission time Handle Problem Language Result Execution time Memory
558040 2022-05-06T14:23:53 Z hoanghq2004 Beads and wires (APIO14_beads) C++14
100 / 100
 198 ms 25724 KB 
#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

const int N = 2e5 + 10;

int n;
vector <pair <int, int> > e[N];
int f[N][2], _w[N], g[N][2];

void down(int u, int p) {
    for (auto [v, w]: e[u]) {
        if (v == p) continue;
        down(v, u);
    }
    int cur[2] = {0, (int)-1e9};
    for (auto [v, w]: e[u]) {
        if (v == p) continue;
        _w[v] = w;
        int ncur[2] = {0, (int)-1e9};
        for (int i = 0; i < 2; ++i) {
            ncur[i] = max(ncur[i], cur[i] + max(f[v][0], f[v][1] + w));
            if (i + 1 < 2) ncur[i + 1] = max(ncur[i + 1], cur[i] + f[v][0] + w);
        }
        for (int i = 0; i < 2; ++i) cur[i] = ncur[i];
    }
    f[u][0] = cur[0];
    f[u][1] = cur[1];
}

int child[N];
int c[N];
int prf[N][2], suf[N][2];

void up(int u, int p) {
    int m = 0;
    for (auto [v, w]: e[u]) {
        if (v == p) continue;
        child[++m] = v;
        c[m] = w;
    }
    prf[0][0] = 0;
    prf[0][1] = -1e9;
    for (int i = 1; i <= m; ++i) {
        int v = child[i];
        int w = c[i];
        prf[i][0] = prf[i - 1][0] + max(f[v][0], f[v][1] + w);
        prf[i][1] = prf[i - 1][1] + max(f[v][0], f[v][1] + w);
        prf[i][1] = max(prf[i][1], prf[i - 1][0] + f[v][0] + w);
    }
    suf[m + 1][0] = 0;
    suf[m + 1][1] = -1e9;
    for (int i = m; i >= 1; --i) {
        int v = child[i];
        int w = c[i];
        suf[i][0] = suf[i + 1][0] + max(f[v][0], f[v][1] + w);
        suf[i][1] = suf[i + 1][1] + max(f[v][0], f[v][1] + w);
        suf[i][1] = max(suf[i][1], suf[i + 1][0] + f[v][0] + w);
    }
    for (int i = 1; i <= m; ++i) {
        int v = child[i];
        g[v][0] = prf[i - 1][0] + suf[i + 1][0] + max(g[u][0], g[u][1] + _w[u]);
        g[v][1] = max({prf[i - 1][0] + suf[i + 1][1] + max(g[u][0], g[u][1] + _w[u]), prf[i - 1][1] + suf[i + 1][0] + max(g[u][0], g[u][1] + _w[u])});
        if (u != 1) g[v][1] = max(g[v][1], prf[i - 1][0] + suf[i + 1][0] + g[u][0] + _w[u]);
    }
    for (auto [v, w]: e[u]) {
        if (v == p) continue;
        up(v, u);
    }
}

int main() {
    ios :: sync_with_stdio(0); cin.tie(0);
    cin >> n;
    for (int i = 1; i < n; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        e[u].push_back({v, w});
        e[v].push_back({u, w});
    }
    down(1, 0);
    g[1][0] = 0, g[1][1] = -1e9;
    up(1, 0);
    int ans = 0;
    for (int r = 1; r <= n; ++r) {
        ans = max(ans, f[r][0] + max(g[r][0], g[r][1] + _w[r]));
    }
    cout << ans;
}

Compilation message

beads.cpp: In function 'void down(int, int)':
beads.cpp:20:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   20 |     for (auto [v, w]: e[u]) {
      |               ^
beads.cpp:25:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   25 |     for (auto [v, w]: e[u]) {
      |               ^
beads.cpp: In function 'void up(int, int)':
beads.cpp:45:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   45 |     for (auto [v, w]: e[u]) {
      |               ^
beads.cpp:74:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   74 |     for (auto [v, w]: e[u]) {
      |               ^

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5024 KB Output is correct
2 Correct 4 ms 5036 KB Output is correct
3 Correct 3 ms 5024 KB Output is correct
4 Correct 3 ms 5028 KB Output is correct
5 Correct 3 ms 4996 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 4 ms 4988 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5024 KB Output is correct
2 Correct 4 ms 5036 KB Output is correct
3 Correct 3 ms 5024 KB Output is correct
4 Correct 3 ms 5028 KB Output is correct
5 Correct 3 ms 4996 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 4 ms 4988 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 5076 KB Output is correct
17 Correct 3 ms 5024 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5008 KB Output is correct
20 Correct 3 ms 4976 KB Output is correct
21 Correct 3 ms 5028 KB Output is correct
22 Correct 4 ms 5024 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5024 KB Output is correct
2 Correct 4 ms 5036 KB Output is correct
3 Correct 3 ms 5024 KB Output is correct
4 Correct 3 ms 5028 KB Output is correct
5 Correct 3 ms 4996 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 4 ms 4988 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 5076 KB Output is correct
17 Correct 3 ms 5024 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5008 KB Output is correct
20 Correct 3 ms 4976 KB Output is correct
21 Correct 3 ms 5028 KB Output is correct
22 Correct 4 ms 5024 KB Output is correct
23 Correct 5 ms 5424 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5332 KB Output is correct
26 Correct 8 ms 5716 KB Output is correct
27 Correct 8 ms 5680 KB Output is correct
28 Correct 7 ms 5936 KB Output is correct
29 Correct 6 ms 5844 KB Output is correct
30 Correct 8 ms 5844 KB Output is correct
31 Correct 8 ms 6200 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5024 KB Output is correct
2 Correct 4 ms 5036 KB Output is correct
3 Correct 3 ms 5024 KB Output is correct
4 Correct 3 ms 5028 KB Output is correct
5 Correct 3 ms 4996 KB Output is correct
6 Correct 3 ms 5076 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 4 ms 4988 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct
13 Correct 3 ms 5076 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 4948 KB Output is correct
16 Correct 4 ms 5076 KB Output is correct
17 Correct 3 ms 5024 KB Output is correct
18 Correct 3 ms 5076 KB Output is correct
19 Correct 3 ms 5008 KB Output is correct
20 Correct 3 ms 4976 KB Output is correct
21 Correct 3 ms 5028 KB Output is correct
22 Correct 4 ms 5024 KB Output is correct
23 Correct 5 ms 5424 KB Output is correct
24 Correct 7 ms 5424 KB Output is correct
25 Correct 5 ms 5332 KB Output is correct
26 Correct 8 ms 5716 KB Output is correct
27 Correct 8 ms 5680 KB Output is correct
28 Correct 7 ms 5936 KB Output is correct
29 Correct 6 ms 5844 KB Output is correct
30 Correct 8 ms 5844 KB Output is correct
31 Correct 8 ms 6200 KB Output is correct
32 Correct 37 ms 8652 KB Output is correct
33 Correct 45 ms 8560 KB Output is correct
34 Correct 26 ms 8620 KB Output is correct
35 Correct 179 ms 19920 KB Output is correct
36 Correct 198 ms 20044 KB Output is correct
37 Correct 192 ms 19968 KB Output is correct
38 Correct 107 ms 24452 KB Output is correct
39 Correct 109 ms 22188 KB Output is correct
40 Correct 109 ms 21620 KB Output is correct
41 Correct 196 ms 25724 KB Output is correct