Submission #162794

#	Time	Username	Problem	Language	Result	Execution time	Memory
162794		DS007	Zagrade (COI17_zagrade)	C++14	0 / 100	171 ms	55048 KiB

zagrade

#include <bits/stdc++.h>
using namespace std;

const int N = 3e5;
string s;
list<int> adj[N];
int n;
long long ans = 0;
map<int, int> m1, m2;

int dfs(int v, int p = -1, int d = INT32_MIN) {
    bool check = true;

    if (d != INT32_MIN) {
        d += s[v] == ')' ? -1 : 1;
        check = false;
        if (s[v] == ')')
            ans += m1[d + 1], m2[d]++;
        else
            ans += m2[d - 1], m1[d]++;
    }

    for (int i : adj[v]) {
        if (i != p) {
            if (d == INT32_MIN)
                d = dfs(i, v) + (s[v] == ')' ? -1 : 1);
            else
                dfs(i, v, d);

            if (check) {
                check = false;
                if (s[v] == ')')
                    ans += m1[d + 1], m2[d]++;
                else
                    ans += m2[d - 1], m1[d]++;
            }
        }
    }

    if (d == INT32_MIN)
        d = s[v] == ')' ? -1 : 1;

    if (check) {
        if (s[v] == ')')
            ans += m1[d + 1], m2[d]++;
        else
            ans += m2[d - 1], m1[d]++;
    }

    return d;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    cin >> n >> s;
    for (int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        u--, v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    dfs(0);
    cout << ans;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60