Submission #8384910

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Source Code Expand

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <limits>
#include <stack>
#include <queue>
#include <map>
#include <set>

using namespace std;

using ll = long long;
using ui = unsigned int;
const ll MOD = 1000000007;
const ll INF = 9223372036854775807;

//AtCoder Regular Contest 097-D
struct LLPair {
	ll a = 0;
	ll b = 0;
};

struct UnionFindTree {
	ll num_node = 0;
	vector<ll> parent;
	vector<ll> count;

	UnionFindTree(ll num_node) {
		this->num_node = num_node;
		parent.clear();
		parent.resize(num_node);
		count.clear();
		count.resize(num_node);
		for (ll i = 0; i < num_node; i++) {
			parent[i] = i;
			count[i] = 1;
		}
	}

	ll FindRoot(ll node) {
		vector<ll> found_node;

		while (true) {
			if (parent[node] == node) {
				for (auto index : found_node) {
					parent[index] = node;
				}
				break;
			}
			else {
				found_node.push_back(node);
				node = parent[node];
			}
		}

		return node;
	}

	bool Unite(ll node1, ll node2) {
		ll node1root = FindRoot(node1);
		ll node2root = FindRoot(node2);

		if (node1root == node2root) {
			return false;
		}

		count[node1root] += count[node2root];
		count[node2root] = 0;
		parent[node2root] = node1root;

		return true;
	}

	ll Count(ll node) {
		return count[FindRoot(node)];
	}
};

int main() {
	ll N;
	scanf("%lld", &N);
	ll M;
	scanf("%lld", &M);
	vector<ll> p(N);
	for (ll i = 0; i < N; i++) {
		scanf("%lld", &p[i]);
	}
	vector<LLPair> sw(M);
	for (ll i = 0; i < M; i++) {
		scanf("%lld %lld", &sw[i].a, &sw[i].b);
	}

	UnionFindTree uf(N);

	for (ll i = 0; i < M; i++) {
		uf.Unite(sw[i].a - 1, sw[i].b - 1);
	}

	ll result = 0;

	for (ll i = 0; i < N; i++) {
		if (uf.FindRoot(p[i] - 1) == uf.FindRoot(i)) {
			result++;
		}		
	}

	printf("%lld\n", result);
}


//AtCoder Grand Contest 019-B
/*
//TLE
int main() {
	char A[202020];
	scanf("%s", A);
	ll len = strlen(A);

	ll result = 1;

	for (ll i = 0; i < len * 2ll - 1ll; i++) { //0:0������ 1:0�����ڂ�1�����ڂ̊� 2:1������
		if (i % 2 == 0) {
			ll index = i / 2;
			ll searchMax = min(index, len - 1 - index);

			//i/2�����ڂ𒆐S
			ll count = 0;
			for (ll j = 1; j <= searchMax; j++) {
				if (A[index - j] != A[index + j]) {
					count++;
				}
			}

			result += count;
		}
		else {
			ll index = i / 2;
			ll searchMax = min(index + 1, len - 1 - index);

			//i/2�����ڂ̉E�𒆐S
			ll count = 0;
			for (ll j = 0; j < searchMax; j++) {
				if (A[index - j] != A[index + j + 1]) {
					count++;
				}
			}

			result += count;
		}
	}

	printf("%lld\n", result);
}
*/

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:84:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &N);
                   ^
./Main.cpp:86:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &M);
                   ^
./Main.cpp:89:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", &p[i]);
                       ^
./Main.cpp:93:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld %lld", &sw[i].a, &sw[i].b);
                                         ^

Judge Result