Submission #545277

#	Time	Username	Problem	Language	Result	Execution time	Memory
545277		tranxuanbach	Zagrade (COI17_zagrade)	C++17	100 / 100	1493 ms	86164 KiB

zagrade

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define fi first
#define se second
#define For(i, l, r) for (auto i = l; i < r; i++)
#define ForE(i, l, r) for (auto i = l; i <= r; i++)
#define FordE(i, l, r) for (auto i = l; i >= r; i--)
#define Fora(v, a) for (auto v: a)
#define bend(a) a.begin(), a.end()
#define isz(a) ((signed)a.size())

using ll = long long;
using ld = long double;
using pii = pair <int, int>;
using vi = vector <int>;
using vpii = vector <pair <int, int>>;
using vvi = vector <vector <int>>;

template <class T>
using ordered_multiset = tree <T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int N = 3e5 + 5;

int n;
string s; int val[N];
vi adj[N];

int par[N], sz[N];

int ctall;
vi adjct[N];
int parct[N], hct[N];

bool block[N];

void dfs_cpn_ct(int u){
    sz[u] = 1;
    Fora(v, adj[u]){
        if (v == par[u] or block[v]){
            continue;
        }
        par[v] = u;
        dfs_cpn_ct(v);
        sz[u] += sz[v];
    }
}

int dfs_ct(int u){
    par[u] = 0;
    dfs_cpn_ct(u);
    if (sz[u] == 1){
        return u;
    }
    int sz_cpn = sz[u];
    while (1){
        int v = 0;
        Fora(tv, adj[u]){
            if (tv == par[u] or block[tv]){
                continue;
            }
            if (sz[tv] * 2 > sz_cpn){
                v = tv;
                break;
            }
        }
        if (v == 0){
            break;
        }
        u = v;
    }
    block[u] = 1;
    Fora(v, adj[u]){
        if (block[v]){
            continue;
        }
        v = dfs_ct(v);
        adjct[u].emplace_back(v);
        parct[v] = u;
    }
    return u;
}

ll ans;

void dfs_cpn_bracket_count(int u, int sum, int mnprefup, int mnprefdown, ordered_multiset <int> &mtsup, ordered_multiset <int> &mtsdown){
    if (sum >= 0 and mnprefup >= 0){
        ans += mtsdown.order_of_key(sum + 1) - mtsdown.order_of_key(sum);
    }
    if (sum <= 0 and mnprefdown == sum){
        ans += mtsup.order_of_key(-sum + 1) - mtsup.order_of_key(-sum);
    }
    Fora(v, adj[u]){
        if (v == par[u] or block[v]){
            continue;
        }
        par[v] = u;
        dfs_cpn_bracket_count(v, sum + val[v], min(val[v], mnprefup + val[v]), min(mnprefdown, sum + val[v]), mtsup, mtsdown);
    }
}

void dfs_cpn_bracket_insert(int u, int sum, int mnprefup, int mnprefdown, ordered_multiset <int> &mtsup, ordered_multiset <int> &mtsdown){
    if (sum >= 0 and mnprefup >= 0){
        mtsup.insert(sum);
    }
    if (sum <= 0 and mnprefdown == sum){
        mtsdown.insert(-sum);
    }
    Fora(v, adj[u]){
        if (v == par[u] or block[v]){
            continue;
        }
        par[v] = u;
        dfs_cpn_bracket_insert(v, sum + val[v], min(val[v], mnprefup + val[v]), min(mnprefdown, sum + val[v]), mtsup, mtsdown);
    }
}

void dfs_bracket(int u){
    ordered_multiset <int> mtsup, mtsdown;
    if (val[u] == 1){
        mtsup.insert(1);
    }
    else{
        mtsdown.insert(1);
    }
    par[u] = 0;
    Fora(v, adj[u]){
        if (block[v]){
            continue;
        }
        par[v] = u;
        dfs_cpn_bracket_count(v, val[v], min(val[v], 0), min(val[v], 0), mtsup, mtsdown);
        dfs_cpn_bracket_insert(v, val[u] + val[v], min({0, val[v], val[v] + val[u]}), min({0, val[u], val[u] + val[v]}), mtsup, mtsdown);
    }
    block[u] = 1;
    Fora(v, adjct[u]){
        dfs_bracket(v);
    }
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen("KEK.inp", "r", stdin);
    // freopen("KEK.out", "w", stdout);
    cin >> n;
    cin >> s; s = ' ' + s;
    For(i, 1, n){
        int u, v; cin >> u >> v;
        adj[u].emplace_back(v); adj[v].emplace_back(u);
    }

    ForE(i, 1, n){
        val[i] = (s[i] == '(' ? 1 : -1);
    }
    ctall = dfs_ct(1);
    memset(block, 0, sizeof(block));
    dfs_bracket(ctall);
    cout << ans << endl;
}

/*
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INPUT:                                            |
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OUTPUT:                                           |
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*/

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 60 / 60