Submission #251812

#TimeUsernameProblemLanguageResultExecution timeMemory
251812VimmerUzastopni (COCI15_uzastopni)C++14
136 / 160
185 ms2048 KiB
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")

#define F first
#define S second
#define sz(x) int(x.size())
#define pb push_back
#define pf push_front
#define N 10010
#define M ll(10007)
#define inf 1e9 + 1e9

using namespace std;
//using namespace __gnu_pbds;

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef short int si;
typedef array <int, 3> a3;
typedef array <int, 4> a4;
typedef pair <int, int> pt;
//typedef tree <int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;


int n, ans, from[N], a[N], siz[N], h[N], l, r;

bool mk[105], mkr[105][105];

vector <int> val[105];

set <int> st[N];

vector <int> g[N];

bool bad;

void dfs_rev(int v)
{
    st[v].insert(a[v]);

    int lst = -1;

    for (auto it : st[v])
    {
        if (lst != -1 && it - lst != 1) {bad = 1; return;}

        lst = it;
    }

    if (v != 1)
    {
        int nxt = from[v];

        if (nxt == 0) {bad = 1; return;}

        if (sz(st[nxt]) < sz(st[v])) swap(st[v], st[nxt]);

        for (auto it : st[v]) st[nxt].insert(it);
    }
    else if (r - l + 1 != sz(st[v])) bad = 1;

}

bool cmp(int x, int y) {return h[x] > h[y];}
bool cmpr(int x, int y) {return h[x] < h[y];}

void dfs(int v)
{
    siz[v] = 1;

    for (auto it : g[v])
    {
        h[it] = h[v] + 1;

        dfs(it);

        siz[v] += siz[it];
    }
}

int main()
{
    //freopen("mining.in", "r", stdin); freopen("mining.out", "w", stdout);

    ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    srand(time(0));

    cin >> n;

    for (int i = 1; i <= n; i++) {cin >> a[i]; val[a[i]].pb(i); mk[a[i]] = 1;}

    for (int i = 1; i < n; i++)
    {
        int x, y;

        cin >> x >> y;

        g[x].pb(y);

        from[y] = x;
    }

    dfs(1);

    for (l = 1; l <= 100; l++)
      if (mk[l])
        for (r = l; r <= 100; r++)
        {
            if (!mk[r]) break;

            if (!(l <= a[1] && a[1] <= r)) continue;

            bad = 0;

            vector <int> gr; gr.clear();

            for (int i = 1; i <= n; i++) st[i].clear();

            for (int i = l; i <= r; i++) gr.pb(val[i][0]);

            sort(gr.begin(), gr.end(), cmp);

            for (auto it : gr) {dfs_rev(it); if (bad) break;}

            if (!bad) {mkr[l][r] = 1; ans++;}
        }

    for (int i = 1; i <= 100; i++) sort(val[i].begin(), val[i].end(), cmpr);

    for (l = 1; l <= 100; l++)
      if (mk[l])
        for (r = l; r <= 100; r++)
        {
            if (!mk[r]) break;

            if (mkr[l][r]) continue;

            if (!(l <= a[1] && a[1] <= r)) continue;

            bad = 0;

            vector <int> gr; gr.clear();

            for (int i = 1; i <= n; i++) st[i].clear();

            for (int i = l; i <= r; i++) gr.pb(val[i][0]);

            sort(gr.begin(), gr.end(), cmp);

            for (auto it : gr) {dfs_rev(it); if (bad) break;}

            if (!bad) {mkr[l][r] = 1; ans++;}
        }

//    for (l = 1; l <= 100; l++)
//      if (mk[l])
//        for (r = l; r <= 100; r++)
//        {
//            if (!mk[r]) break;
//
//            if (mkr[l][r]) continue;
//
//            if (!(l <= a[1] && a[1] <= r)) continue;
//
//            bad = 0;
//
//            vector <int> gr; gr.clear();
//
//            for (int i = 1; i <= n; i++) st[i].clear();
//
//            for (int i = l; i <= r; i++) gr.pb(val[i][rand() % sz(val[i])]);
//
//            sort(gr.begin(), gr.end(), cmp);
//
//            for (auto it : gr) {dfs_rev(it); if (bad) break;}
//
//            if (!bad) {mkr[l][r] = 1; ans++;}
//        }

    cout << ans << endl;
}
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