oj.uz

Submission #50798

# Submission time Handle Problem Language Result Execution time Memory
50798 2018-06-13T10:49:16 Z waynetuinfor Beads and wires (APIO14_beads) C++17
100 / 100
 316 ms 39016 KB 
#include <bits/stdc++.h>
using namespace std;

const int maxn = 1e6 + 5;
const long long inf = 1e15;
vector<pair<int, int>> graf[maxn];
long long dp[2][maxn], ans;

void dfs(int x, int p) {
    dp[0][x] = 0; dp[1][x] = -inf;
    for (auto u : graf[x]) if (u.first != p) {
        dfs(u.first, x);
        dp[0][x] += max(dp[1][u.first] + u.second, dp[0][u.first]);
    }
    for (auto u : graf[x]) if (u.first != p) {
        long long t = max(dp[1][u.first] + u.second, dp[0][u.first]);
        dp[1][x] = max(dp[1][x], dp[0][x] - t + dp[0][u.first] + u.second);
    }
}

void dfsans(int x, int p, long long f, long long t0, long long t1) {
    long long k0 = dp[0][x] + max(t1 + f, t0);
    ans = max(ans, k0);
    pair<long long, int> p1 = make_pair(-inf, -1), p2 = make_pair(-inf, -1);
    for (auto u : graf[x]) if (u.first != p) {
        long long k = max(dp[1][u.first] + u.second, dp[0][u.first]);
        long long c = -k + dp[0][u.first] + u.second;
        pair<long long, int> pt = make_pair(c, u.first);
        if (pt > p1) p2 = p1, p1 = pt;
        else if (pt > p2) p2 = pt;
    }
    for (auto u : graf[x]) if (u.first != p) {
        long long z0 = k0 - max(dp[1][u.first] + u.second, dp[0][u.first]);
        long long z1 = z0 - max(t1 + f, t0) + t0 + f;
        z1 = max(z1, z0 + (p1.second == u.first ? p2.first : p1.first));
        dfsans(u.first, x, u.second, z0, z1);
    }
}

int main() {
    int n; scanf("%d", &n);
    for (int i = 0; i < n - 1; ++i) {
        int a, b, c; scanf("%d %d %d", &a, &b, &c);
        graf[a].emplace_back(b, c);
        graf[b].emplace_back(a, c);
    }
    dfs(1, 0);
    ans = -inf;
    dfsans(1, 0, -inf, 0, -inf);
    printf("%lld%c\n", ans, (char)(13));
    return 0;
}

Compilation message

beads.cpp: In function 'int main()':
beads.cpp:41:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     int n; scanf("%d", &n);
            ~~~~~^~~~~~~~~~
beads.cpp:43:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         int a, b, c; scanf("%d %d %d", &a, &b, &c);
                      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 22 ms 23808 KB Output is correct
4 Correct 21 ms 23808 KB Output is correct
5 Correct 22 ms 23808 KB Output is correct
6 Correct 22 ms 23800 KB Output is correct
7 Correct 21 ms 23808 KB Output is correct
8 Correct 22 ms 23808 KB Output is correct
9 Correct 21 ms 23808 KB Output is correct
10 Correct 21 ms 23808 KB Output is correct
11 Correct 23 ms 23808 KB Output is correct
12 Correct 21 ms 23808 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 22 ms 23808 KB Output is correct
4 Correct 21 ms 23808 KB Output is correct
5 Correct 22 ms 23808 KB Output is correct
6 Correct 22 ms 23800 KB Output is correct
7 Correct 21 ms 23808 KB Output is correct
8 Correct 22 ms 23808 KB Output is correct
9 Correct 21 ms 23808 KB Output is correct
10 Correct 21 ms 23808 KB Output is correct
11 Correct 23 ms 23808 KB Output is correct
12 Correct 21 ms 23808 KB Output is correct
13 Correct 22 ms 23808 KB Output is correct
14 Correct 22 ms 23808 KB Output is correct
15 Correct 22 ms 23808 KB Output is correct
16 Correct 22 ms 23808 KB Output is correct
17 Correct 22 ms 23808 KB Output is correct
18 Correct 23 ms 23800 KB Output is correct
19 Correct 23 ms 23808 KB Output is correct
20 Correct 23 ms 23808 KB Output is correct
21 Correct 22 ms 23800 KB Output is correct
22 Correct 23 ms 23808 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 22 ms 23808 KB Output is correct
4 Correct 21 ms 23808 KB Output is correct
5 Correct 22 ms 23808 KB Output is correct
6 Correct 22 ms 23800 KB Output is correct
7 Correct 21 ms 23808 KB Output is correct
8 Correct 22 ms 23808 KB Output is correct
9 Correct 21 ms 23808 KB Output is correct
10 Correct 21 ms 23808 KB Output is correct
11 Correct 23 ms 23808 KB Output is correct
12 Correct 21 ms 23808 KB Output is correct
13 Correct 22 ms 23808 KB Output is correct
14 Correct 22 ms 23808 KB Output is correct
15 Correct 22 ms 23808 KB Output is correct
16 Correct 22 ms 23808 KB Output is correct
17 Correct 22 ms 23808 KB Output is correct
18 Correct 23 ms 23800 KB Output is correct
19 Correct 23 ms 23808 KB Output is correct
20 Correct 23 ms 23808 KB Output is correct
21 Correct 22 ms 23800 KB Output is correct
22 Correct 23 ms 23808 KB Output is correct
23 Correct 26 ms 24064 KB Output is correct
24 Correct 25 ms 24064 KB Output is correct
25 Correct 26 ms 24064 KB Output is correct
26 Correct 30 ms 24320 KB Output is correct
27 Correct 29 ms 24320 KB Output is correct
28 Correct 27 ms 24448 KB Output is correct
29 Correct 27 ms 24288 KB Output is correct
30 Correct 27 ms 24312 KB Output is correct
31 Correct 29 ms 24696 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 22 ms 23808 KB Output is correct
4 Correct 21 ms 23808 KB Output is correct
5 Correct 22 ms 23808 KB Output is correct
6 Correct 22 ms 23800 KB Output is correct
7 Correct 21 ms 23808 KB Output is correct
8 Correct 22 ms 23808 KB Output is correct
9 Correct 21 ms 23808 KB Output is correct
10 Correct 21 ms 23808 KB Output is correct
11 Correct 23 ms 23808 KB Output is correct
12 Correct 21 ms 23808 KB Output is correct
13 Correct 22 ms 23808 KB Output is correct
14 Correct 22 ms 23808 KB Output is correct
15 Correct 22 ms 23808 KB Output is correct
16 Correct 22 ms 23808 KB Output is correct
17 Correct 22 ms 23808 KB Output is correct
18 Correct 23 ms 23800 KB Output is correct
19 Correct 23 ms 23808 KB Output is correct
20 Correct 23 ms 23808 KB Output is correct
21 Correct 22 ms 23800 KB Output is correct
22 Correct 23 ms 23808 KB Output is correct
23 Correct 26 ms 24064 KB Output is correct
24 Correct 25 ms 24064 KB Output is correct
25 Correct 26 ms 24064 KB Output is correct
26 Correct 30 ms 24320 KB Output is correct
27 Correct 29 ms 24320 KB Output is correct
28 Correct 27 ms 24448 KB Output is correct
29 Correct 27 ms 24288 KB Output is correct
30 Correct 27 ms 24312 KB Output is correct
31 Correct 29 ms 24696 KB Output is correct
32 Correct 61 ms 26444 KB Output is correct
33 Correct 63 ms 26488 KB Output is correct
34 Correct 56 ms 26488 KB Output is correct
35 Correct 270 ms 34424 KB Output is correct
36 Correct 264 ms 34552 KB Output is correct
37 Correct 272 ms 34552 KB Output is correct
38 Correct 180 ms 34788 KB Output is correct
39 Correct 180 ms 34904 KB Output is correct
40 Correct 197 ms 34832 KB Output is correct
41 Correct 316 ms 39016 KB Output is correct