oj.uz

Submission #677851

# Submission time Handle Problem Language Result Execution time Memory
677851 2023-01-04T12:45:28 Z dooompy Pipes (BOI13_pipes) C++17
100 / 100
 119 ms 18288 KB 
#include "bits/stdc++.h"

using namespace std;

void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T a, U ...b) {
    cout << a << ' ', abc(b...);
}
template <typename T> void printv(T l, T r) {
    while (l != r) cout << *l << " \n"[++l == r];
}
template <typename A, typename B> istream& operator >> (istream& o, pair<A, B> &a) {
    return o >> a.first >> a.second;
}
template <typename A, typename B> ostream& operator << (ostream& o, pair<A, B> a) {
    return o << '(' << a.first << ", " << a.second << ')';
}
template <typename T> ostream& operator << (ostream& o, vector<T> a) {
    bool is = false;
    for (T i : a) {o << (is ? ' ' : '{'), is = true, o << i;}
    return o << '}';
}

#ifdef local
#define test(args...) abc("[" + string(#args) + "]", args)
#else
#define test(args...) void(0)
#endif

using ll = long long;

ll v[500005];

set<int> adj[100005];
ll calc[500005];
int en[500005], out[500005];

vector<pair<int, int>> ord;

void dfs(int cur, int p, int root) {

    int idx = *adj[cur].begin();

    int nxtidx = (en[idx] == cur ? out[idx] : en[idx]);

    if (nxtidx == p) {
        idx = *adj[cur].rbegin();

        nxtidx = (en[idx] == cur ? out[idx] : en[idx]);
    }

    ord.push_back({cur, idx});

    if (nxtidx != root) dfs(nxtidx, cur, root);
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
//    freopen("test.txt", "r", stdin);
//    freopen("", "w", stdout);
    int n, m; cin >> n >> m;

    if (m > n) {
        cout << 0 << endl;
        return 0;
    }

    for (int i = 1; i <= n; i++) cin >> v[i];
    for (int i = 1; i <= m; i++) {
        int a, b; cin >> a >> b;
        en[i] = a, out[i] = b;
        adj[a].insert(i);
        adj[b].insert(i);
    }

    queue<int> q;

    for (int i = 1; i <= n; i++) {
            q.push(i);

    }

    while (!q.empty()) {
        // deg 1
        auto cur = q.front(); q.pop();

        if (adj[cur].size() == 1) {
            int idx = *adj[cur].begin();

            int nxtidx = (en[idx] == cur ? out[idx] : en[idx]);
            ll weight = v[cur];

            v[nxtidx] -= v[cur];
            v[cur] -= v[cur];

            calc[idx] = 2LL * weight;

            adj[cur].erase(idx);
            adj[nxtidx].erase(idx);

            if (adj[nxtidx].size() == 1) q.push(nxtidx);
        }
    }

    int ct = 0;

    for (int i = 1; i <= n; i++) {
        if (adj[i].size() > 2) {
            cout << 0;
            return 0;
        }

        ct += (adj[i].size() == 2);
    }

    if (ct % 2 == 0 && ct > 0) {
        cout << 0;
        return 0;
    }

    if (m == n - 1) {
        for (int i = 1; i <= m; i++) {
            cout << calc[i]  << "\n";
        }
        return 0;
    }
    int left = 1;
    for (; left <= n; left++) {
        if (adj[left].size() == 2) break;
    }

    dfs(left, -1, left);

//    assert(ord.size() == left.size());

//    for (auto x : ord) cout << x << " ";

    ll prev = 0;

    for (int i = 1; i < ord.size() ; i++) {
        // assum back ->0 is X

        prev = 2LL * v[ord[i].first] - prev;

    }

    ll x = (2LL * v[ord[0].first] - prev) / 2;

//    cout << x << endl;

    calc[ord[0].second] = x;

    for (int i = 1; i < ord.size(); i++) {
        calc[ord[i].second] = 2LL * v[ord[i].first] - calc[ord[i-1].second];
    }


    for (int i = 1; i <= m; i++) {
        cout << calc[i] << "\n";
    }
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:141:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  141 |     for (int i = 1; i < ord.size() ; i++) {
      |                     ~~^~~~~~~~~~~~
pipes.cpp:154:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  154 |     for (int i = 1; i < ord.size(); i++) {
      |                     ~~^~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 3 ms 5076 KB Output is correct
4 Correct 95 ms 17520 KB Output is correct
5 Correct 4 ms 4948 KB Output is correct
6 Correct 3 ms 4948 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 4948 KB Output is correct
9 Correct 4 ms 5076 KB Output is correct
10 Correct 3 ms 5076 KB Output is correct
11 Correct 3 ms 5076 KB Output is correct
12 Correct 3 ms 5076 KB Output is correct
13 Correct 76 ms 14916 KB Output is correct
14 Correct 85 ms 16812 KB Output is correct
15 Correct 103 ms 17612 KB Output is correct
16 Correct 83 ms 15636 KB Output is correct
17 Correct 99 ms 17472 KB Output is correct
18 Correct 119 ms 17612 KB Output is correct
19 Correct 87 ms 17596 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 5076 KB Output is correct
22 Correct 94 ms 17564 KB Output is correct
23 Correct 85 ms 14924 KB Output is correct
24 Correct 102 ms 17528 KB Output is correct
25 Correct 72 ms 15508 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 5076 KB Output is correct
3 Correct 70 ms 16500 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 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 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5076 KB Output is correct
16 Correct 3 ms 5076 KB Output is correct
17 Correct 3 ms 5076 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 2 ms 4948 KB Output is correct
20 Correct 3 ms 4948 KB Output is correct
21 Correct 3 ms 4948 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 66 ms 15632 KB Output is correct
24 Correct 88 ms 18048 KB Output is correct
25 Correct 75 ms 16380 KB Output is correct
26 Correct 3 ms 4968 KB Output is correct
27 Correct 3 ms 4948 KB Output is correct
28 Correct 2 ms 4948 KB Output is correct
29 Correct 2 ms 4948 KB Output is correct
30 Correct 85 ms 17832 KB Output is correct
31 Correct 84 ms 18288 KB Output is correct
32 Correct 99 ms 17644 KB Output is correct
33 Correct 74 ms 17080 KB Output is correct
34 Correct 3 ms 4948 KB Output is correct
35 Correct 2 ms 4948 KB Output is correct
36 Correct 3 ms 4972 KB Output is correct
37 Correct 3 ms 4948 KB Output is correct
38 Correct 89 ms 17932 KB Output is correct
39 Correct 101 ms 17476 KB Output is correct
40 Correct 88 ms 17972 KB Output is correct
41 Correct 56 ms 17088 KB Output is correct
42 Correct 2 ms 4948 KB Output is correct
43 Correct 2 ms 4948 KB Output is correct
44 Correct 3 ms 4948 KB Output is correct
45 Correct 3 ms 4948 KB Output is correct
46 Correct 90 ms 17844 KB Output is correct
47 Correct 103 ms 18032 KB Output is correct
48 Correct 84 ms 18244 KB Output is correct
49 Correct 78 ms 16468 KB Output is correct
50 Correct 3 ms 4948 KB Output is correct
51 Correct 4 ms 4948 KB Output is correct
52 Correct 2 ms 4948 KB Output is correct
53 Correct 3 ms 4948 KB Output is correct
54 Correct 98 ms 17656 KB Output is correct