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Submission #1051120

# Submission time Handle Problem Language Result Execution time Memory
1051120 2024-08-09T20:22:21 Z ortsac Pipes (BOI13_pipes) C++17
100 / 100
 90 ms 39668 KB 
#include <bits/stdc++.h>
 
using namespace std;

#define int long long
#define pii pair<long long, long long>
#define fr first
#define se second

const int MAXN = 1e5 + 10;
const int MAXM = 5e5 + 10;
vector<pii> adj[MAXN];
int bEdge = -1;
vector<pii> edges;
int h[MAXN];
int change[MAXN];
bool vis[MAXN];
int dad[MAXN];
int dp[MAXN];
int peso[MAXM];

void dfs(int node) {
    vis[node] = 1;
    for (auto [u, z] : adj[node]) {
        if (u == dad[node]) continue;
        if (vis[u]) bEdge = z;
        else {
            dad[u] = node;
            h[u] = h[node] + 1;
            dfs(u);
        }
    }
}

void calc(int node) {
    vis[node] = 1;
    for (auto [u, z] : adj[node]) {
        if (vis[u]) continue;
        calc(u);
        dp[node] += (change[u] - dp[u]);
        peso[z] += (change[u] - dp[u]);
    }
}

vector<int> path;
bool found = 0;
int need;

void cPath(int from, int to) {
    path.clear();
    while (to != from) {
        path.push_back(to);
        to = dad[to];
    }
    path.push_back(from);
    reverse(path.begin(), path.end());
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> change[i];
    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        edges.push_back({a, b});
        adj[a].push_back({b, i});
        adj[b].push_back({a, i});
    }
    if (m > n) {
        cout << "0\n";
        return 0;
    }
    dfs(1);
    int lca = 0;
    if (bEdge != -1) {
        auto u = edges[bEdge];
        int a = u.fr, b = u.se;
        if (h[b] > h[a]) swap(a, b);
        lca = b;
        int tam = h[a] + h[b] - 2*h[lca] + 1;
        if ((tam % 2LL) == 0) {
            cout << "0\n";
            return 0;
        }
    }
    memset(vis, 0, sizeof vis);
    calc(1);
    if (dp[1] == change[1]) {
        for (int i = 0; i < m; i++) cout << 2*peso[i] << "\n";
        return 0;
    }
    // first case is for tree
    // second case is if you can't add 2x to it
    if ((bEdge == -1) || ((change[1] - dp[1]) % 2LL)) {
        cout << "0\n";
        return 0;
    }
    need = (change[1] - dp[1])/2LL;
    cPath(1, lca);
    int tam = path.size();
    int inv = 1;
    for (int i = 0; i < (tam - 1); i++) {
        int node = path[i];
        int prox = path[i + 1];
        for (auto [u, z] : adj[node]) {
            if (u == prox) {
                peso[z] += 2*need*inv;
                inv = -inv;
                break;
            }
        }
    }
    int a = edges[bEdge].fr, b = edges[bEdge].se;
    if (h[b] > h[a]) swap(a, b);
    cPath(lca, a);
    tam = path.size();
    for (int i = 0; i < (tam - 1); i++) {
        int node = path[i];
        int prox = path[i + 1];
        for (auto [u, z] : adj[node]) {
            if (u == prox) {
                peso[z] += need*inv;
                inv = -inv;
                break;
            }
        }
    }
    if ((h[a] - h[lca]) % 2LL) inv = -inv;
    peso[bEdge] += inv*need;
    for (int i = 0; i < m; i++) {
        cout << 2*peso[i] << "\n";
    }
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 5468 KB Output is correct
2 Correct 1 ms 5468 KB Output is correct
3 Correct 1 ms 5724 KB Output is correct
4 Correct 33 ms 17024 KB Output is correct
5 Correct 1 ms 5464 KB Output is correct
6 Correct 1 ms 5468 KB Output is correct
7 Correct 1 ms 5468 KB Output is correct
8 Correct 1 ms 5468 KB Output is correct
9 Correct 1 ms 5724 KB Output is correct
10 Correct 1 ms 5724 KB Output is correct
11 Correct 1 ms 5724 KB Output is correct
12 Correct 1 ms 5724 KB Output is correct
13 Correct 26 ms 13772 KB Output is correct
14 Correct 29 ms 14996 KB Output is correct
15 Correct 36 ms 15300 KB Output is correct
16 Correct 27 ms 14276 KB Output is correct
17 Correct 30 ms 16832 KB Output is correct
18 Correct 31 ms 17100 KB Output is correct
19 Correct 35 ms 20868 KB Output is correct
20 Correct 1 ms 5468 KB Output is correct
21 Correct 1 ms 5724 KB Output is correct
22 Correct 35 ms 17056 KB Output is correct
23 Correct 26 ms 13772 KB Output is correct
24 Correct 31 ms 15304 KB Output is correct
25 Correct 30 ms 15876 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 5464 KB Output is correct
2 Correct 1 ms 5724 KB Output is correct
3 Correct 25 ms 14740 KB Output is correct
4 Correct 22 ms 12452 KB Output is correct
5 Correct 21 ms 11980 KB Output is correct
6 Correct 88 ms 39668 KB Output is correct
7 Correct 1 ms 5468 KB Output is correct
8 Correct 1 ms 5468 KB Output is correct
9 Correct 1 ms 5464 KB Output is correct
10 Correct 1 ms 5468 KB Output is correct
11 Correct 1 ms 5468 KB Output is correct
12 Correct 1 ms 5468 KB Output is correct
13 Correct 1 ms 5468 KB Output is correct
14 Correct 1 ms 5468 KB Output is correct
15 Correct 1 ms 5724 KB Output is correct
16 Correct 1 ms 5724 KB Output is correct
17 Correct 1 ms 5724 KB Output is correct
18 Correct 1 ms 5724 KB Output is correct
19 Correct 1 ms 5724 KB Output is correct
20 Correct 1 ms 5720 KB Output is correct
21 Correct 1 ms 5724 KB Output is correct
22 Correct 1 ms 5724 KB Output is correct
23 Correct 33 ms 18996 KB Output is correct
24 Correct 37 ms 20424 KB Output is correct
25 Correct 25 ms 14528 KB Output is correct
26 Correct 22 ms 12224 KB Output is correct
27 Correct 25 ms 12236 KB Output is correct
28 Correct 23 ms 12748 KB Output is correct
29 Correct 71 ms 34172 KB Output is correct
30 Correct 43 ms 24508 KB Output is correct
31 Correct 40 ms 25476 KB Output is correct
32 Correct 32 ms 16844 KB Output is correct
33 Correct 28 ms 15816 KB Output is correct
34 Correct 23 ms 12236 KB Output is correct
35 Correct 22 ms 12228 KB Output is correct
36 Correct 24 ms 12280 KB Output is correct
37 Correct 90 ms 39256 KB Output is correct
38 Correct 37 ms 21956 KB Output is correct
39 Correct 37 ms 16316 KB Output is correct
40 Correct 37 ms 21696 KB Output is correct
41 Correct 32 ms 17600 KB Output is correct
42 Correct 22 ms 12236 KB Output is correct
43 Correct 22 ms 12188 KB Output is correct
44 Correct 28 ms 12076 KB Output is correct
45 Correct 69 ms 36528 KB Output is correct
46 Correct 40 ms 23488 KB Output is correct
47 Correct 46 ms 20160 KB Output is correct
48 Correct 39 ms 23488 KB Output is correct
49 Correct 22 ms 12736 KB Output is correct
50 Correct 21 ms 12236 KB Output is correct
51 Correct 24 ms 12236 KB Output is correct
52 Correct 21 ms 12232 KB Output is correct
53 Correct 80 ms 35584 KB Output is correct
54 Correct 37 ms 21200 KB Output is correct