oj.uz

Submission #13568

# Submission time Handle Problem Language Result Execution time Memory
13568 2015-02-24T13:30:19 Z gs14004 Shymbulak (IZhO14_shymbulak) C++14
26.67 / 100
 1500 ms 27512 KB 
#include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
typedef long long lint;
typedef pair<int,lint> pi;

int n;

vector<int> graph[200005];
int deg[200005];

int piv;
int cycle_num[200005];
int get_cycle[200005];
int vis[200005];
pi cycle_ret[200005];

long long freq[200005];

void label_graph(){
    queue<int> q;
    for (int i=1; i<=n; i++) {
        if(deg[i] == 1){
            q.push(i);
        }
    }
    while (!q.empty()) {
        int x = q.front();
        q.pop();
        deg[x] = 0;
        for (int &i : graph[x]){
            if(deg[i]){
                deg[i]--;
                if(deg[i] == 1){
                    q.push(i);
                }
            }
        }
    }
    for (int i=1; i<=n; i++) {
        if(deg[i]){
            q.push(i);
            break;
        }
    }
    while (!q.empty()) {
        int x = q.front();
        q.pop();
        cycle_num[x] = ++piv;
        get_cycle[cycle_num[x]] = x;
        for (int &i : graph[x]){
            if(deg[i] && !cycle_num[i]){
                q.push(i);
                break;
            }
        }
    }
    for (int i=1; i<=n; i++) {
        if(cycle_num[i]){
            q.push(i);
            vis[i] = 1;
            while (!q.empty()) {
                int x = q.front();
                q.pop();
                for (int &i : graph[x]){
                    if(!vis[i]){
                        vis[i] = 1;
                        q.push(i);
                    }
                }
            }
        }
    }
}

bool cmp(pi a, pi b){
    return a.first > b.first;
}

pi f(int x, int pa){
    vector<pi> sub;
    for (int &i : graph[x]){
        if(i == pa) continue;
        if(cycle_num[i]) continue;
        pi t = f(i,x);
        t.first++;
        sub.push_back(t);
    }
    sort(sub.begin(),sub.end(),cmp);
    if(sub.size() == 0) return pi(0,1);
    if(sub.size() == 1){
        freq[sub[0].first] += sub[0].second;
        return sub[0];
    }
    if(sub[0].first == sub[1].first){
        pi t(sub[0].first,0);
        for (int i=0; i<sub.size(); i++) {
            if(sub[0].first == sub[i].first) t.second += sub[i].second;
        }
        long long sum = 1ll * t.second * t.second;
        for (int i=0; i<sub.size(); i++) {
            if(sub[0].first == sub[i].first) sum -= 1ll * sub[i].second * sub[i].second;
        }
        sum /= 2;
        freq[t.first * 2] += sum;
        return t;
    }
    int low_sub = 0;
    for (int i=1; i<sub.size(); i++) {
        if(sub[1].first == sub[i].first) low_sub += sub[i].second;
    }
    freq[sub[0].first + sub[1].first] += 1ll * low_sub * sub[0].second;
    return sub[0];
}

int main(){
    scanf("%d",&n);
    for (int i=0; i<n; i++) {
        int s,e;
        scanf("%d %d",&s,&e);
        graph[s].push_back(e);
        graph[e].push_back(s);
        deg[s]++;
        deg[e]++;
    }
    label_graph();
    for (int i=1; i<=n; i++) {
        if(cycle_num[i]){
            cycle_ret[i] = f(i,0);
        }
    }
    for (int i=1; i<=piv; i++) {
        for (int j=i+1; j<=piv; j++) {
            int pi = get_cycle[i], pj = get_cycle[j];
            if(j-i == n - j + i){
                int lng = cycle_ret[pi].first + cycle_ret[pj].first + j - i;
                freq[lng] += cycle_ret[pi].second * cycle_ret[pj].second * 2ll;
            }
            else{
                int lng = cycle_ret[pi].first + cycle_ret[pj].first + min(j-i,n-j+i);
                freq[lng] += cycle_ret[pi].second * cycle_ret[pj].second;
            }
        }
    }
    for (int i=n; i; i--) {
        if(freq[i]){
            printf("%lld",freq[i]);
            return 0;
        }
    }
}

Subtask #1
4.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14084 KB Output is correct
2 Incorrect 0 ms 14084 KB Output isn't correct
3 Incorrect 0 ms 14084 KB Output isn't correct
4 Correct 3 ms 14084 KB Output is correct
5 Incorrect 3 ms 14084 KB Output isn't correct
6 Incorrect 0 ms 14084 KB Output isn't correct
7 Incorrect 0 ms 14084 KB Output isn't correct
8 Incorrect 0 ms 14084 KB Output isn't correct
9 Incorrect 0 ms 14084 KB Output isn't correct
10 Incorrect 3 ms 14084 KB Output isn't correct
11 Incorrect 0 ms 14084 KB Output isn't correct
12 Incorrect 1 ms 14084 KB Output isn't correct
13 Incorrect 3 ms 14084 KB Output isn't correct
14 Incorrect 0 ms 14084 KB Output isn't correct
15 Incorrect 0 ms 14084 KB Output isn't correct

Subtask #2
6.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14084 KB Output is correct
2 Incorrect 4 ms 14084 KB Output isn't correct
3 Incorrect 0 ms 14084 KB Output isn't correct
4 Incorrect 0 ms 14084 KB Output isn't correct
5 Incorrect 0 ms 14216 KB Output isn't correct
6 Incorrect 3 ms 14396 KB Output isn't correct
7 Correct 7 ms 14216 KB Output is correct
8 Correct 0 ms 14216 KB Output is correct
9 Incorrect 2 ms 14216 KB Output isn't correct
10 Incorrect 0 ms 14216 KB Output isn't correct

Subtask #3
16.667 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 58 ms 17248 KB Output is correct
2 Correct 72 ms 17644 KB Output is correct
3 Execution timed out 1500 ms 17248 KB Program timed out
4 Incorrect 46 ms 17380 KB Output isn't correct
5 Incorrect 53 ms 17512 KB Output isn't correct
6 Correct 154 ms 20020 KB Output is correct
7 Correct 101 ms 19164 KB Output is correct
8 Incorrect 121 ms 20812 KB Output isn't correct
9 Incorrect 150 ms 20812 KB Output isn't correct
10 Incorrect 197 ms 21208 KB Output isn't correct
11 Incorrect 120 ms 27200 KB Output isn't correct
12 Incorrect 126 ms 27512 KB Output isn't correct