oj.uz

Submission #383224

# Submission time Handle Problem Language Result Execution time Memory
383224 2021-03-29T08:48:41 Z fammo Pipes (BOI13_pipes) C++11
96.1111 / 100
 186 ms 26728 KB 
#include <bits/stdc++.h>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;
#define X first
#define Y second
#define pb push_back
#define fastio ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#define rndom mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())

#define endl '\n'
//#define int long long
const int  N = 100 * 1000 + 20, L = 20, M = 100 * 1000 + 20;////////////////ya5e5
int n, m, c[N], ans[M], a[N], h[N], par[N];
vector<int>adj[N], ind[N];
int edg[N];
void dfst(int v, int p){
    int id = -1;
    for(int i = 0; i < (int)adj[v].size(); i ++){
        int u = adj[v][i], ed = ind[v][i];
        if(u == p){id = ed; continue;}
        dfst(u, v);
        a[v] -= ans[ed];
    }
    if(id!= -1)ans[id] = a[v], a[v] = 0;
}
void solvetree(){
    dfst(0, -1);
    for(int i = 0; i < n; i ++)if(a[i] != 0){cout << 0 << endl; exit(0);}
    for(int i = 0; i < m; i ++)cout << ans[i] << endl;
    exit(0);
}
bool mark[N], dead[M], cyc[M], seen[N];
int S = -1, sz = 0;
void markcyc(int v, int u){//cyc u --- v(-backedge-)u
    if(h[u] < h[v])swap(u,v);
    seen[v] = 1;
    while(u != v){
        seen[u] = 1;
        cyc[edg[u]] = 1;
        u = par[u];
    }return;
}
void pre(int v, int id = -1){
    mark[v] = 1;
    for(int i = 0; i < (int)adj[v].size() ; i ++){
        int u = adj[v][i], ed = ind[v][i];
        //cout << "ADJ " << u << " VIA " << ed << endl;
        if(ed == id)continue;
        if(!mark[u]){
            par[u] = v;
            h[u] = h[v] + 1;
            pre(u, ed);
        }
    }
    edg[v] = id;
}
void findcyc(int v, int id = -1){
   // cout << "HERE " << v << " FROM " << id << endl;
    mark[v] = 1;
    for(int i = 0; i < (int)adj[v].size() ; i ++){
        int u = adj[v][i], ed = ind[v][i];
        //cout << "ADJ " << u << " VIA " << ed << endl;
        if(ed == id)continue;
        if(mark[u]){
            if((h[v] - h[u])%2){
               // cout << "h" <<v << " -h" << u << " = " << h[v] -h[u] << endl;
                cout << 0 << endl;
                exit(0);
            }
            cyc[ed] = 1;
            S=v;sz = abs(h[u]-h[v])+1;
            markcyc(v,u);
        }else{
            par[u] = v;
            h[u] = h[v] + 1;
            findcyc(u, ed);
        }
    }
    return;
}
void dfs(int v, int id = -1){
    mark[v] = 1;
    for(int i = 0; i < (int)adj[v].size(); i ++){
        int u = adj[v][i], ed = ind[v][i];
        if(!mark[u])dfs(u,ed);
        a[v] -= ans[ed];
    }
    if(id != -1 && !seen[v])ans[id] = a[v], a[v] = 0;
    return;
}
int32_t main(){
    fastio;
    ///auto t = clock();
    cin >> n >> m;
    if(m > n) return cout << 0 << endl, 0;
    for(int i = 0; i < n; i ++)cin >> c[i], a[i] = c[i]*2;
    for(int i = 0; i < m; i ++){
        int u, v; cin >> u >> v;
        u --; v --;
        adj[u].pb(v), adj[v].pb(u);
        ind[u].pb(i), ind[v].pb(i);
    }
    if(m == n - 1) solvetree();
    ////////////////////////////////////////////////////////////////////////////////
    /// \brief findcyc
    pre(0);
    for(int i = 0; i < n; i ++)mark[i] = 0;
    findcyc(0);int root = 0;
    for(int i = 0;i < n; i ++){mark[i] = 0; if((int)adj[i].size() != 1)root = i;}
    dfs(root);

    vector<int>vec;
    int cur = S, pr = -1;
    for(int t = 0; t < sz; t ++){
        for(int i = 0; i < (int)adj[cur].size(); i ++){
            int u = adj[cur][i], ed =ind[cur][i];
            if(cyc[ed] && u != pr){
                vec.pb(ed);
                if(pr == -1){
                    ans[ed] = 0;
                }else{
                    ans[ed] = a[cur];
                    a[cur]=0;
                    a[u]-=ans[ed];
                }pr= cur; cur = u;goto hell;
            }
        }
        hell:;
    }
    //cout << "S : " << S << ": " << a[S] << endl;
    int df = a[S]/2;
    ans[vec[0]] = df;
    for(int i = 1; i < (int)vec.size(); i ++){ans[vec[i]] -= df; df*=-1;}

    for(int i = 0; i < m; i ++)cout << ans[i] << '\n';
    ///cout << clock() - t << "ms" << endl;
    return 0;

}

/*13 13
3 7 6 8 -2 -4 12 -5 17 -6 1 0 3
1 2
2 3
3 5
5 9
9 8
5 13
13 10
13 7
7 11
11 12
11 6
7 4
4 3*/

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5100 KB Output is correct
2 Correct 5 ms 5100 KB Output is correct
3 Correct 6 ms 5228 KB Output is correct
4 Correct 112 ms 14700 KB Output is correct
5 Correct 4 ms 5120 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 5 ms 5100 KB Output is correct
9 Correct 6 ms 5104 KB Output is correct
10 Correct 5 ms 5228 KB Output is correct
11 Correct 6 ms 5228 KB Output is correct
12 Correct 5 ms 5228 KB Output is correct
13 Correct 85 ms 12780 KB Output is correct
14 Correct 105 ms 14188 KB Output is correct
15 Correct 117 ms 14864 KB Output is correct
16 Correct 90 ms 13344 KB Output is correct
17 Correct 109 ms 14700 KB Output is correct
18 Correct 121 ms 14828 KB Output is correct
19 Correct 121 ms 18412 KB Output is correct
20 Correct 4 ms 5100 KB Output is correct
21 Correct 5 ms 5228 KB Output is correct
22 Correct 119 ms 14956 KB Output is correct
23 Correct 81 ms 12780 KB Output is correct
24 Correct 110 ms 14700 KB Output is correct
25 Correct 91 ms 13164 KB Output is correct

Subtask #2
66.1111111111 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 5100 KB Output is correct
2 Correct 5 ms 5356 KB Output is correct
3 Correct 111 ms 19308 KB Output is correct
4 Correct 4 ms 5100 KB Output is correct
5 Correct 5 ms 5100 KB Output is correct
6 Correct 4 ms 5100 KB Output is correct
7 Correct 4 ms 5100 KB Output is correct
8 Correct 4 ms 5100 KB Output is correct
9 Correct 4 ms 5100 KB Output is correct
10 Correct 4 ms 5100 KB Output is correct
11 Correct 4 ms 5100 KB Output is correct
12 Correct 4 ms 5100 KB Output is correct
13 Correct 4 ms 5100 KB Output is correct
14 Correct 4 ms 5100 KB Output is correct
15 Correct 6 ms 5368 KB Output is correct
16 Correct 5 ms 5228 KB Output is correct
17 Correct 5 ms 5228 KB Output is correct
18 Correct 4 ms 5100 KB Output is correct
19 Correct 4 ms 5100 KB Output is correct
20 Correct 4 ms 5100 KB Output is correct
21 Correct 5 ms 5100 KB Output is correct
22 Incorrect 5 ms 5228 KB Output isn't correct
23 Correct 137 ms 20260 KB Output is correct
24 Correct 172 ms 22148 KB Output is correct
25 Correct 111 ms 19308 KB Output is correct
26 Correct 5 ms 5100 KB Output is correct
27 Correct 4 ms 5100 KB Output is correct
28 Correct 4 ms 5100 KB Output is correct
29 Correct 5 ms 5100 KB Output is correct
30 Correct 179 ms 25576 KB Output is correct
31 Correct 182 ms 25956 KB Output is correct
32 Correct 155 ms 18284 KB Output is correct
33 Correct 122 ms 21100 KB Output is correct
34 Correct 4 ms 5100 KB Output is correct
35 Correct 4 ms 5100 KB Output is correct
36 Correct 5 ms 5100 KB Output is correct
37 Correct 6 ms 5100 KB Output is correct
38 Correct 184 ms 24436 KB Output is correct
39 Incorrect 148 ms 17388 KB Output isn't correct
40 Incorrect 175 ms 21868 KB Output isn't correct
41 Correct 131 ms 24556 KB Output is correct
42 Correct 4 ms 5100 KB Output is correct
43 Correct 4 ms 5100 KB Output is correct
44 Correct 4 ms 5100 KB Output is correct
45 Correct 4 ms 5100 KB Output is correct
46 Correct 175 ms 26728 KB Output is correct
47 Correct 186 ms 21872 KB Output is correct
48 Correct 182 ms 25700 KB Output is correct
49 Correct 105 ms 16296 KB Output is correct
50 Correct 4 ms 5100 KB Output is correct
51 Correct 4 ms 5228 KB Output is correct
52 Correct 4 ms 5100 KB Output is correct
53 Correct 4 ms 5100 KB Output is correct
54 Correct 175 ms 23532 KB Output is correct