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Submission #31625

# Submission time Handle Problem Language Result Execution time Memory
31625 2017-08-30T04:05:59 Z minkank Beads and wires (APIO14_beads) C++14
100 / 100
 793 ms 103284 KB 
#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> ii;

const int N = 2e5 + 5;

int n, dp[N][2], ans, g[N][2], cnt[N];
vector<ii> a[N], b[N];
vector<int> l[N], r[N], sax[2][N], cax[2][N];

void dfs(int u, int p) {
    dp[u][0] = dp[u][1] = 0;
    cnt[u] = 0;
    for(int i = 0; i < a[u].size(); ++i) {
        int v = a[u][i].first;
        if(v == p) continue;
        dfs(v, u);
        cnt[u]++; b[u][cnt[u]] = a[u][i];
    }
    l[u][0] = 0;
    for(int i = 1; i <= cnt[u]; ++i) {
        int v = b[u][i].first, w = b[u][i].second;
        l[u][i] = l[u][i - 1] + max(dp[v][1] + w, dp[v][0]);
    }
    r[u][cnt[u] + 1] = 0;
    for(int i = cnt[u]; i >= 1; --i) {
        int v = b[u][i].first, w = b[u][i].second;
        r[u][i] = r[u][i + 1] + max(dp[v][1] + w, dp[v][0]);
    }
    dp[u][0] = l[u][cnt[u]];
    for(int i = 1; i <= cnt[u]; ++i) {
        int v = b[u][i].first, w = b[u][i].second;
        dp[u][1] = max(dp[u][1], l[u][i - 1] + r[u][i + 1] + dp[v][0] + w);
    }
    if(a[u].size() == 1) dp[u][1] = -1e9;
}

void redfs(int u, int p) {
    if(a[p].size() == 1) g[p][1] = -1e9;
    sax[1][u][0] = -1e9;
    for(int i = 1; i <= cnt[u]; ++i) {
        int v = b[u][i].first, w = b[u][i].second;
        sax[0][u][i] = sax[0][u][i - 1] + max(dp[v][1] + w, dp[v][0]);
        sax[1][u][i] = sax[0][u][i - 1] + w + dp[v][0];
        sax[1][u][i] = max(sax[1][u][i], sax[1][u][i - 1] + max(dp[v][1] + w, dp[v][0]));
    }
    int W = 0;
    for(int i = 0; i < a[u].size(); ++i) if(a[u][i].first == p) W = a[u][i].second;
    if(u != 1) {
        cax[0][u][cnt[u] + 1] = max(g[p][1] + W, g[p][0]);
        cax[1][u][cnt[u] + 1] = W + g[p][0];
    }
    else cax[0][u][cnt[u] + 1] = 0, cax[1][u][cnt[u] + 1] = -1e9;
    for(int i = cnt[u]; i >= 1; --i) {
        int v = b[u][i].first, w = b[u][i].second;
        cax[0][u][i] = cax[0][u][i + 1] + max(dp[v][1] + w, dp[v][0]);
        cax[1][u][i] = cax[0][u][i + 1] + w + dp[v][0];
        cax[1][u][i] = max(cax[1][u][i], cax[1][u][i + 1] + max(dp[v][1] + w, dp[v][0]));
    }
    ans = max(ans, cax[0][u][1]);
    for(int i = 1; i <= cnt[u]; ++i) {
        int v = b[u][i].first;
        g[u][0] = sax[0][u][i - 1] + cax[0][u][i + 1];
        g[u][1] = max(sax[1][u][i - 1] + cax[0][u][i + 1], sax[0][u][i - 1] + cax[1][u][i + 1]);
        redfs(v, u);
    }
}

void get(int &x) {
    x = 0;
    char c = getchar();
    while(c < '0' || c > '9') c = getchar();
    while('0' <= c && c <= '9') x = (x << 3) + (x << 1) + c - '0', c = getchar();
}

int main() {
    get(n);
    for(int i = 1; i < n; ++i) {
        int u, v, w;
        get(u); get(v); get(w);
        a[u].push_back(ii(v, w));
        a[v].push_back(ii(u, w));
    }
    for(int i = 1; i <= n; ++i) l[i].assign(a[i].size() + 3, 0), r[i].assign(a[i].size() + 3, 0), b[i].assign(a[i].size() + 3, ii(0, 0)), sax[0][i].assign(a[i].size() + 3, 0), sax[1][i].assign(a[i].size() + 3, 0), cax[0][i].assign(a[i].size() + 3, 0), cax[1][i].assign(a[i].size() + 3, 0);
    dfs(1, 1);
    redfs(1, 1);
    cout << ans;
}

Compilation message

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < a[u].size(); ++i) {
                    ~~^~~~~~~~~~~~~
beads.cpp: In function 'void redfs(int, int)':
beads.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < a[u].size(); ++i) if(a[u][i].first == p) W = a[u][i].second;
                    ~~^~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 38008 KB Output is correct
2 Correct 33 ms 37880 KB Output is correct
3 Correct 34 ms 37908 KB Output is correct
4 Correct 34 ms 37888 KB Output is correct
5 Correct 35 ms 38008 KB Output is correct
6 Correct 35 ms 37888 KB Output is correct
7 Correct 35 ms 37888 KB Output is correct
8 Correct 36 ms 37888 KB Output is correct
9 Correct 36 ms 37880 KB Output is correct
10 Correct 37 ms 37880 KB Output is correct
11 Correct 35 ms 38016 KB Output is correct
12 Correct 36 ms 37888 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 38008 KB Output is correct
2 Correct 33 ms 37880 KB Output is correct
3 Correct 34 ms 37908 KB Output is correct
4 Correct 34 ms 37888 KB Output is correct
5 Correct 35 ms 38008 KB Output is correct
6 Correct 35 ms 37888 KB Output is correct
7 Correct 35 ms 37888 KB Output is correct
8 Correct 36 ms 37888 KB Output is correct
9 Correct 36 ms 37880 KB Output is correct
10 Correct 37 ms 37880 KB Output is correct
11 Correct 35 ms 38016 KB Output is correct
12 Correct 36 ms 37888 KB Output is correct
13 Correct 36 ms 37884 KB Output is correct
14 Correct 36 ms 37888 KB Output is correct
15 Correct 35 ms 38008 KB Output is correct
16 Correct 37 ms 38016 KB Output is correct
17 Correct 35 ms 38008 KB Output is correct
18 Correct 36 ms 38016 KB Output is correct
19 Correct 36 ms 38008 KB Output is correct
20 Correct 36 ms 38016 KB Output is correct
21 Correct 36 ms 38008 KB Output is correct
22 Correct 33 ms 38016 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 38008 KB Output is correct
2 Correct 33 ms 37880 KB Output is correct
3 Correct 34 ms 37908 KB Output is correct
4 Correct 34 ms 37888 KB Output is correct
5 Correct 35 ms 38008 KB Output is correct
6 Correct 35 ms 37888 KB Output is correct
7 Correct 35 ms 37888 KB Output is correct
8 Correct 36 ms 37888 KB Output is correct
9 Correct 36 ms 37880 KB Output is correct
10 Correct 37 ms 37880 KB Output is correct
11 Correct 35 ms 38016 KB Output is correct
12 Correct 36 ms 37888 KB Output is correct
13 Correct 36 ms 37884 KB Output is correct
14 Correct 36 ms 37888 KB Output is correct
15 Correct 35 ms 38008 KB Output is correct
16 Correct 37 ms 38016 KB Output is correct
17 Correct 35 ms 38008 KB Output is correct
18 Correct 36 ms 38016 KB Output is correct
19 Correct 36 ms 38008 KB Output is correct
20 Correct 36 ms 38016 KB Output is correct
21 Correct 36 ms 38008 KB Output is correct
22 Correct 33 ms 38016 KB Output is correct
23 Correct 41 ms 39416 KB Output is correct
24 Correct 63 ms 39428 KB Output is correct
25 Correct 41 ms 39416 KB Output is correct
26 Correct 48 ms 41080 KB Output is correct
27 Correct 51 ms 41080 KB Output is correct
28 Correct 48 ms 41120 KB Output is correct
29 Correct 50 ms 41136 KB Output is correct
30 Correct 46 ms 41080 KB Output is correct
31 Correct 46 ms 41336 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 38008 KB Output is correct
2 Correct 33 ms 37880 KB Output is correct
3 Correct 34 ms 37908 KB Output is correct
4 Correct 34 ms 37888 KB Output is correct
5 Correct 35 ms 38008 KB Output is correct
6 Correct 35 ms 37888 KB Output is correct
7 Correct 35 ms 37888 KB Output is correct
8 Correct 36 ms 37888 KB Output is correct
9 Correct 36 ms 37880 KB Output is correct
10 Correct 37 ms 37880 KB Output is correct
11 Correct 35 ms 38016 KB Output is correct
12 Correct 36 ms 37888 KB Output is correct
13 Correct 36 ms 37884 KB Output is correct
14 Correct 36 ms 37888 KB Output is correct
15 Correct 35 ms 38008 KB Output is correct
16 Correct 37 ms 38016 KB Output is correct
17 Correct 35 ms 38008 KB Output is correct
18 Correct 36 ms 38016 KB Output is correct
19 Correct 36 ms 38008 KB Output is correct
20 Correct 36 ms 38016 KB Output is correct
21 Correct 36 ms 38008 KB Output is correct
22 Correct 33 ms 38016 KB Output is correct
23 Correct 41 ms 39416 KB Output is correct
24 Correct 63 ms 39428 KB Output is correct
25 Correct 41 ms 39416 KB Output is correct
26 Correct 48 ms 41080 KB Output is correct
27 Correct 51 ms 41080 KB Output is correct
28 Correct 48 ms 41120 KB Output is correct
29 Correct 50 ms 41136 KB Output is correct
30 Correct 46 ms 41080 KB Output is correct
31 Correct 46 ms 41336 KB Output is correct
32 Correct 143 ms 53388 KB Output is correct
33 Correct 148 ms 53368 KB Output is correct
34 Correct 133 ms 53368 KB Output is correct
35 Correct 645 ms 99896 KB Output is correct
36 Correct 652 ms 99960 KB Output is correct
37 Correct 649 ms 99828 KB Output is correct
38 Correct 564 ms 102784 KB Output is correct
39 Correct 562 ms 101332 KB Output is correct
40 Correct 793 ms 102184 KB Output is correct
41 Correct 697 ms 103284 KB Output is correct