Submission #40174

#	Time	Username	Problem	Language	Result	Execution time	Memory
40174		krauch	Zagrade (COI17_zagrade)	C++14	100 / 100	1378 ms	51308 KiB

zagrade

/*
 _    _    _______   _    _
| |  / /  |  _____| | |  / /
| | / /   | |       | | / /
| |/ /    | |_____  | |/ /
| |\ \    |  _____| | |\ \
| | \ \   | |       | | \ \
| |  \ \  | |_____  | |  \ \
|_|   \_\ |_______| |_|   \_\

*/
#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef double ld;
typedef pair <int, int> PII;
typedef pair <ll, ll> PLL;
typedef pair < ll, int > PLI;


#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define right(x) x << 1 | 1
#define left(x) x << 1
#define forn(x, a, b) for (int x = a; x <= b; ++x)
#define for1(x, a, b) for (int x = a; x >= b; --x)
#define mkp make_pair
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define y1 kekekek

#define fname ""

const ll ool = 1e18 + 9;
const int oo = 1e9 + 9, base = 1e9 + 7;
const ld eps = 1e-7;
const int N = 5e5 + 6;

int n, ROOT = 0, cnt[N], tmp[N], MXVAL;
bool u[N];
char a[N];
vector < int > g[N];
ll ans;

int getsz(int v, int par, int sz) {
    int res = 1;
    bool ok = 1;
    for (auto to : g[v]) {
        if (to == par || u[to]) continue;
        int val = getsz(to, v, sz);
        if (val > sz / 2) ok = 0;
        res += val;
    }
    if (sz - res > sz / 2) ok = 0;
    if (ok) ROOT = v;
    return res;
}

void dfs(int v, int par, int bal, int mn) {
    bal += (a[v] == ')' ? -1 : 1);
    mn = min(mn, bal);
    if (bal == mn) cnt[-bal]++;
    for (auto to : g[v]) {
        if (to == par || u[to]) continue;
        dfs(to, v, bal, mn);
    }
}

void calc(int v, int par, int bal, int mn, int bal2, int mx, int kek) {
    bal += (a[v] == ')' ? -1 : 1);
    bal2 += (a[v] == ')' ? -1 : 1);
    mn = min(mn, bal);
    mx = max(mx, bal2);
    if (bal == mn) cnt[-bal] -= kek;
    if (bal == mn) MXVAL = max(MXVAL, abs(bal));
    if (bal2 == mx) tmp[bal2] += kek;
    if (bal2 == mx) MXVAL = max(MXVAL, abs(bal2));
    for (auto to : g[v]) {
        if (to == par || u[to]) continue;
        calc(to, v, bal, mn, bal2, mx, kek);
    }
}

void build(int v, int sz) {
    getsz(v, 0, sz);
    int root = ROOT;
    //cerr << root << " " << sz << "\n";
    forn(i, 0, sz / 2 + 1) cnt[i] = 0;
    dfs(root, 0, 0, 0);
    for (auto to : g[root]) {
        if (u[to]) continue;
        MXVAL = 0;
        calc(to, root, (a[root] == ')' ? -1 : 1), (a[root] == ')' ? -1 : 1), 0, 0, 1);
        forn(i, 0, MXVAL) {
            ans += 1ll * cnt[i] * tmp[i];
            //cerr << root << " " << to << " " << i << " " << cnt[i] << " " << tmp[i] << "\n";
        }
        calc(to, root, (a[root] == ')' ? -1 : 1), (a[root] == ')' ? -1 : 1), 0, 0, -1);
    }
    ans += cnt[0];
    //cerr << "kek " << cnt[0] << "\n";

    u[root] = 1;
    vector < int > vec;
    for (auto to : g[root]) {
        vec.eb(0);
        if (u[to]) continue;
        vec.back() = getsz(to, root, sz);
    }
    forn(i, 0, sz(g[root]) - 1) {
        if (u[g[root][i]]) continue;
        build(g[root][i], vec[i]);
    }
}

int main() {
	//ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

	#ifdef krauch
        freopen("input.txt", "r", stdin);
    #else
        //freopen(fname".in", "r", stdin);
        //freopen(fname".out", "w", stdout);
    #endif

    scanf("%d\n", &n);
    forn(i, 1, n) {
        scanf("%c", a + i);
    }
    scanf("\n");

    forn(i, 1, n - 1) {
        int x, y;
        scanf("%d %d\n", &x, &y);
        g[x].eb(y);
        g[y].eb(x);
    }

    build(1, n);

    cout << ans << "\n";

	return 0;
}

Compilation message (stderr)

zagrade.cpp: In function 'int main()':
zagrade.cpp:131:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d\n", &n);
                      ^
zagrade.cpp:133:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%c", a + i);
                           ^
zagrade.cpp:135:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("\n");
                ^
zagrade.cpp:139:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d\n", &x, &y);
                                 ^

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