Submission #392503

#	Time	Username	Problem	Language	Result	Execution time	Memory
392503		patrikpavic2	Shymbulak (IZhO14_shymbulak)	C++17	50 / 100	51 ms	22876 KiB

shymbulak

#include <cstdio>
#include <vector>
#include <algorithm>
#include <stack>
#include <cstdlib>

#define X first
#define Y second
#define PB push_back

using namespace std;

typedef long long ll;
typedef pair < int, ll > pil;

const int N = 2e5 + 500;
const int OFF = (1 << 18);

pil add(pil A, pil B){
	return {max(A.X, B.X), A.Y * (A.X >= B.X) + B.Y * (B.X >= A.X)};
}

pil mul(pil A, pil B){
	return {A.X + B.X, A.Y * B.Y};
}

int un[N], n;
vector < int > v[N];
vector < int > cik;
pil sol = {0, 0};
pil ja[N];

pil f(int x, int lst){
	pil dep = {0, 1};
	for(int y : v[x]){
		if(y == lst || un[y]) continue;
		pil nxt = f(y, x);
		sol = add(sol, mul(dep, nxt));
		dep = add(dep, nxt);
	}
	dep.X++;
	return dep;
}

int bio[N];
stack < int > S;

void dfs(int x, int lst){
	if((int)cik.size() != 0) return;
	if(bio[x]){
		cik.PB(x);
		while(S.top() != x)
			cik.PB(S.top()), S.pop();
		return;			
	}
	bio[x] = 1;
	S.push(x);
	for(int y : v[x])
		if(y != lst)
			dfs(y, x);
	S.pop();
}


int main(){
	scanf("%d", &n);
	for(int i = 0;i < n;i++){
		int x, y; scanf("%d%d", &x, &y);
		v[x].PB(y), v[y].PB(x);
	}
	dfs(1, 1);
	for(int x : cik) un[x] = 1;
	for(int i = 0;i < (int)cik.size();i++)
		ja[i] = f(cik[i], cik[i]), ja[i].X--;
	int m = (int)cik.size();
	for(int i = 0;i < m;i++){
		for(int j = i + 1;j < m;j++){
			pil kof = {min(abs(i - j), m - abs(i - j)), 1 + (2 * abs(i - j) == m)};
			sol = add(sol, mul(mul(ja[i], ja[j]), kof));
		}
	}
	printf("%lld\n", sol.Y);
	return 0;
}

Compilation message (stderr)

shymbulak.cpp: In function 'int main()':
shymbulak.cpp:66:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   66 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
shymbulak.cpp:68:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   68 |   int x, y; scanf("%d%d", &x, &y);
      |             ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20
• Subtask 3: 0 / 50