oj.uz

Submission #253849

# Submission time Handle Problem Language Result Execution time Memory
253849 2020-07-28T22:14:28 Z aZvezda Pipes (BOI13_pipes) C++14
74.0741 / 100
 252 ms 31096 KB 
#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC target ("sse4")
#define endl "\n"
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
template<class T, class T2> inline bool chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline bool chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const ll mod = 1e9 + 7;
template<class T> inline void fix(T &x) {if(x >= mod | x <= -mod) {x %= mod;} if(x < 0) {x += mod;}}
#define out(x) cout << __LINE__ << ": " << (#x) << " = " << (x) << endl


//If we have an even cycle then we can add 1 on odd edges and -1 on even edges so the solutions stay the same. We can remove leaves one by one

const ll MAX_N = 1e5 + 10;
set<pair<ll, ll> > g[MAX_N];
ll ans[MAX_N], arr[MAX_N];

struct cmp {
    bool operator ()(const ll &a, const ll &b) const {
        if(g[a].size() == g[b].size()) {
            return a < b;
        }
        return g[a].size() < g[b].size();
    }
};

multiset<ll, cmp> pq;

void removeBranches() {
    while(!pq.empty() && g[*(pq.begin())].size() == 1) {
        ll curr = *(pq.begin()); pq.erase(pq.begin());
        auto other = *(g[curr].begin());
        pq.erase(other.first);
        ans[other.second] = 2 * arr[curr];
        arr[other.first] -= arr[curr];
        g[other.first].erase({curr, other.second});
        pq.insert(other.first);
    }
}

int rret = 0;

void dfs(int x, int p, int start, int flag) {
    rret += arr[x] * flag;
    //cout << x << " " << p << " " << ans[x] << " " << rret << endl;
    for(auto it : g[x]) {
        if(it.first == p || it.first == start) {continue;}
        dfs(it.first, x, start, -flag);
    }
}

void removeCycle() {
    if(pq.size() < 2) {return;}
    auto now = pq.begin();
    if(g[*now].size() > 2) {
        cout << 0 << endl;
        exit(0);
    }
    now = pq.end(); now --;
    if(g[*now].size() > 2) {
        cout << 0 << endl;
        exit(0);
    }
    if(pq.size() % 2 == 0) {
        cout << 0 << endl;
        exit(0);
    }
    int curr = *(pq.begin());
    dfs(curr, (*(g[curr].begin())).first, curr, 1);
    rret /= 2;
    auto sec = (g[curr].begin());
    arr[curr] -= rret;
    arr[(*sec).first] -= rret;
    ans[(*sec).second] = rret;
    pq.erase(curr);
    pq.erase((*sec).first);
    g[curr].erase(sec);
    g[(*sec).first].erase({curr, (*sec).second});
    pq.insert(curr);
    pq.insert((*sec).first);
    //cout << curr << " " << (*sec).first << " " << rret << endl;
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    ll n, m;
    cin >> n >> m;
    if(m > n) {cout << 0 << endl; return 0;}
    for(ll i = 1; i <= n; i ++) {
        cin >> arr[i];
    }
    for(ll i = 0; i < m; i ++) {
        ll a, b;
        cin >> a >> b;
        g[a].insert({b, i});
        g[b].insert({a, i});
    }
    for(ll i = 1; i <= n; i ++) {
        pq.insert(i);
    }
    removeBranches();
    removeCycle();
    removeBranches();
    for(ll i = 0; i < m; i ++) {
        cout << ans[i] << endl;
    }
    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4992 KB Output is correct
2 Correct 3 ms 4992 KB Output is correct
3 Correct 4 ms 5248 KB Output is correct
4 Correct 230 ms 24184 KB Output is correct
5 Correct 3 ms 4992 KB Output is correct
6 Correct 3 ms 4992 KB Output is correct
7 Correct 3 ms 4992 KB Output is correct
8 Correct 3 ms 4992 KB Output is correct
9 Correct 4 ms 5248 KB Output is correct
10 Correct 4 ms 5248 KB Output is correct
11 Correct 4 ms 5248 KB Output is correct
12 Correct 4 ms 5248 KB Output is correct
13 Correct 164 ms 20252 KB Output is correct
14 Correct 206 ms 23160 KB Output is correct
15 Correct 219 ms 24312 KB Output is correct
16 Correct 180 ms 21368 KB Output is correct
17 Correct 220 ms 24184 KB Output is correct
18 Correct 222 ms 24248 KB Output is correct
19 Correct 171 ms 24312 KB Output is correct
20 Correct 3 ms 4992 KB Output is correct
21 Correct 4 ms 5248 KB Output is correct
22 Correct 225 ms 24240 KB Output is correct
23 Correct 166 ms 20216 KB Output is correct
24 Correct 225 ms 24312 KB Output is correct
25 Correct 182 ms 20984 KB Output is correct

Subtask #2
44.0740740741 / 70.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 4992 KB Output isn't correct
2 Incorrect 4 ms 5248 KB Output isn't correct
3 Correct 154 ms 22648 KB Output is correct
4 Correct 3 ms 4992 KB Output is correct
5 Correct 3 ms 4992 KB Output is correct
6 Correct 3 ms 4992 KB Output is correct
7 Incorrect 3 ms 4992 KB Output isn't correct
8 Incorrect 3 ms 5120 KB Output isn't correct
9 Correct 3 ms 4992 KB Output is correct
10 Correct 3 ms 4992 KB Output is correct
11 Correct 3 ms 4992 KB Output is correct
12 Correct 3 ms 4992 KB Output is correct
13 Correct 3 ms 4992 KB Output is correct
14 Incorrect 3 ms 4992 KB Output isn't correct
15 Incorrect 4 ms 5248 KB Output isn't correct
16 Incorrect 4 ms 5248 KB Output isn't correct
17 Correct 4 ms 5248 KB Output is correct
18 Correct 3 ms 4992 KB Output is correct
19 Correct 3 ms 4992 KB Output is correct
20 Correct 3 ms 4992 KB Output is correct
21 Correct 3 ms 4992 KB Output is correct
22 Incorrect 6 ms 5248 KB Output isn't correct
23 Incorrect 183 ms 24696 KB Output isn't correct
24 Incorrect 213 ms 28348 KB Output isn't correct
25 Correct 153 ms 22648 KB Output is correct
26 Correct 4 ms 4992 KB Output is correct
27 Correct 3 ms 4992 KB Output is correct
28 Correct 3 ms 4992 KB Output is correct
29 Correct 3 ms 4992 KB Output is correct
30 Incorrect 186 ms 27384 KB Output isn't correct
31 Incorrect 201 ms 31096 KB Output isn't correct
32 Incorrect 225 ms 25592 KB Output isn't correct
33 Correct 170 ms 24056 KB Output is correct
34 Correct 3 ms 5120 KB Output is correct
35 Correct 3 ms 4992 KB Output is correct
36 Correct 3 ms 4992 KB Output is correct
37 Correct 3 ms 4992 KB Output is correct
38 Incorrect 206 ms 27896 KB Output isn't correct
39 Incorrect 222 ms 25080 KB Output isn't correct
40 Incorrect 215 ms 28024 KB Output isn't correct
41 Correct 107 ms 23800 KB Output is correct
42 Correct 3 ms 4992 KB Output is correct
43 Correct 3 ms 4992 KB Output is correct
44 Correct 3 ms 4992 KB Output is correct
45 Correct 4 ms 4992 KB Output is correct
46 Incorrect 183 ms 27384 KB Output isn't correct
47 Incorrect 219 ms 28172 KB Output isn't correct
48 Incorrect 207 ms 30840 KB Output isn't correct
49 Correct 252 ms 22648 KB Output is correct
50 Correct 4 ms 4992 KB Output is correct
51 Correct 3 ms 4992 KB Output is correct
52 Correct 3 ms 4992 KB Output is correct
53 Correct 3 ms 4992 KB Output is correct
54 Incorrect 213 ms 26872 KB Output isn't correct