Submission #204736

#	Time	Username	Problem	Language	Result	Execution time	Memory
204736		BorisBarca	Zagrade (COI17_zagrade)	C++14	0 / 100	582 ms	41584 KiB

zagrade

/*
$$$$$$$\                      $$\           $$$$$$$\
$$  __$$\                     \__|          $$  __$$\
$$ |  $$ | $$$$$$\   $$$$$$\  $$\  $$$$$$$\ $$ |  $$ | $$$$$$\   $$$$$$\   $$$$$$$\ $$$$$$\
$$$$$$$\ |$$  __$$\ $$  __$$\ $$ |$$  _____|$$$$$$$\ | \____$$\ $$  __$$\ $$  _____|\____$$\
$$  __$$\ $$ /  $$ |$$ |  \__|$$ |\$$$$$$\  $$  __$$\  $$$$$$$ |$$ |  \__|$$ /      $$$$$$$ |
$$ |  $$ |$$ |  $$ |$$ |      $$ | \____$$\ $$ |  $$ |$$  __$$ |$$ |      $$ |     $$  __$$ |
$$$$$$$  |\$$$$$$  |$$ |      $$ |$$$$$$$  |$$$$$$$  |\$$$$$$$ |$$ |      \$$$$$$$\\$$$$$$$ |
\_______/  \______/ \__|      \__|\_______/ \_______/  \_______|\__|       \_______|\_______|
*/
#include <bits/stdc++.h>

using namespace std;

#define PB push_back
#define MP make_pair
#define INS insert
#define LB lower_bound
#define UB upper_bound
#define pii pair <int,int>
#define pll pair <long long, long long>
#define si pair<string, int>
#define is pair<int, string>
#define X first
#define Y second
#define _ << " " <<
#define sz(x) (int)x.size()
#define all(a) (a).begin(),(a).end()
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORD(i, a, b) for (int i = (a); i > (b); --i)
#define FORR(i, l, r) for (int i = (l); i <= (r); ++i)
#define FORP(i, a, b) for ((i) = (a); (i) < (b); ++i)
#define FORA(i, x) for (auto &i : x)
#define REP(i, n) FOR(i, 0, n)
#define BITS(x) __builtin_popcount(x)
#define MSET memset
#define MCPY memcpy
#define SQ(a) (a) * (a)
#define TRACE(x) cout << #x " = " << (x) << '\n';
#define YES cout << "YES\n"
#define NO cout << "NO\n"

typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef vector <pii> vpi;
typedef vector <ll> vll;
typedef vector <pll> vpl;
typedef vector <double> vd;
typedef vector <ld> vld;
typedef vector<si> vsi;
typedef vector<is> vis;
typedef vector<string> vs;
//((float) t)/CLOCKS_PER_SEC

const int MOD = 1e9 + 7;
const double PI = acos(-1);
const int INF = 1e9 + 10;
const ll INFL = 1e18 + 10;
const int ABC = 30;
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const int dox[] = {-1, 1, 0, 0, -1, -1, 1, 1};
const int doy[] = {0, 0, -1, 1, -1, 1, -1, 1};

inline int sum(int a, int b){
	if (a + b < 0)
		return (a + b + MOD) % MOD;
	return (a + b) % MOD;
}

inline void add(int &a, int b){
	a = sum(a, b);
}

inline int mul(int a, int b){
	return (ll)a * (ll)b % MOD;
}

inline int sub(int a, int b){
	return (a - b + MOD) % MOD;
}

inline int pot(ll pot, int n){
	ll ret = 1;
	while (n){
		if (n & 1)
			ret = (ret * pot) % MOD;
			pot = (pot * pot) % MOD;
			n >>= 1;
		}
	return ret;
}

inline int divide(int a, int b){
	return mul(a, pot(b, MOD - 2));
}

ll lcm(ll a, ll b){
	return abs(a * b) / __gcd(a, b);
}

inline double ccw(pii A, pii B, pii C){
	return (A.X * B.Y) - (A.Y * B.X) + (B.X * C.Y) - (B.Y * C.X) + (C.X * A.Y) - (C.Y * A.X);
}

inline int CCW(pii A, pii B, pii C){
	double val = ccw(A, B, C);
	double eps = max(max(abs(A.X), abs(A.Y)), max(max(abs(B.X), abs(B.Y)), max(abs(C.X), abs(C.Y)))) / 1e9;
	if (val <= -eps)
		return -1;
	if (val >= eps)
		return 1;
	return 0;
}

void to_upper(string &x){
	REP(i, sz(x))
		x[i] = toupper(x[i]);
}

void to_lower(string &x){
	REP(i, sz(x))
		x[i] = tolower(x[i]);
}

string its(ll x){
	if (x == 0)
		return "0";
	string ret = "";
	while (x > 0){
		ret += (x % 10) + '0';
		x /= 10;
	}
	reverse(all(ret));
	return ret;
}

ll sti(string s){
	ll ret = 0;
	REP(i, sz(s)){
		ret *= 10;
		ret += (s[i] - '0');
	}
	return ret;
}

const int N = 3e5 + 10;

int n, sz[N], centroid;
string s;
vi e[N];
bool is_centroid[N], ok_here[N];
map <int, int> cnt;
ll sol;

void dfs(int node, int dad){
	sz[node] = 1;
	FORA(nxt, e[node])
		if (nxt != dad && !is_centroid[nxt]){
			dfs(nxt, node);
			sz[node] += sz[nxt];
		}
}

void find_centroid(int node, int dad, int component_size){
	int maxi = component_size - sz[node];
	FORA(nxt, e[node]){
		if (nxt == dad || is_centroid[nxt])
			continue;
		find_centroid(nxt, node, component_size);
		maxi = max(maxi, sz[nxt]);
	}
	if (maxi <= component_size / 2)
		centroid = node;
}

void calc_end(int node, int dad, int z, int open){
	if (!is_centroid[node]){
		if (s[node] == ')')
			z--, open--;
		else 
			z++, open++;
		open = max(open, 0);
		cnt[z]++;
	}

	if (open == 0)
		cnt[z]++;

	//cout << node + 1 _ z _ open << '\n';

	FORA(nxt, e[node]){
		if (nxt == dad || is_centroid[nxt])
			continue;
		calc_end(nxt, node, z, open);
	}
}

void solve(int node, int dad, int z, int open){
	if (s[node] == '(')
		z++, open--;
	else
		z--, open++;

	open = max(open, 0);

	if (open == 0)
		sol += cnt[-z];

	//cout << node + 1 _ ok_here[node] _ cnt[-z] _ z << '\n';

	FORA(nxt, e[node]){
		if (nxt == dad || is_centroid[nxt])
			continue;
		solve(nxt, node, z, open);
	}
}

void decompose(int node){
	dfs(node, -1);
	if (sz[node] == 1)
		return;

	cnt.clear();

	find_centroid(node, -1, sz[node]);
	assert(centroid != -1);
	is_centroid[centroid] = 1;

	calc_end(centroid, -1, 0, 0);
	solve(centroid, -1, 0, 0);

	//cout << "-------\n";

	FORA(nxt, e[centroid])
		if (!is_centroid[nxt])
			decompose(nxt);
}

int main () {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	cin >> n >> s;
	REP(i, n - 1){
		int x, y; cin >> x >> y;
		x--, y--;
		e[x].PB(y);
		e[y].PB(x);
	}

	decompose(1);
	cout << (sol + 1) / 2 << '\n';

	return 0;
}

Compilation message (stderr)

zagrade.cpp: In function 'int pot(ll, int)':
zagrade.cpp:87:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   if (n & 1)
   ^~
zagrade.cpp:89:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
    pot = (pot * pot) % MOD;
    ^~~

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