Submission #1160539

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Source Code Expand

#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

static const double EPS = 1e-8;
static const double PI = 4.0 * atan(1.0);
static const double PI2 = 8.0 * atan(1.0);

#define REP(i,n)	for(int i=0;i<(int)n;++i)
#define ALL(c)		(c).begin(),(c).end()
#define CLEAR(v)	memset(v,0,sizeof(v))
#define MP(a,b)		make_pair((a),(b))
#define ABS(a)		((a)>0?(a):-(a))
#define FOR(i,s,n)	for(int i=s;i<(int)n;++i)

int n, m;
vector<int> es[100000];

int conn[100000];

void dfs(int v, int val) {
	if (conn[v] == val) return;
	conn[v] = val;
	REP(i, es[v].size()) dfs(es[v][i], val);
}

int main(int argc, char **argv) {
	cin >> n >> m;
	REP(i, m) {
		int a, b;
		cin >> a >> b;
		--a; --b;
		es[a].push_back(b);
		es[b].push_back(a);
	}

	memset(conn, -1, sizeof(conn));
	int v = 0;
	REP(i, n) if (conn[i] < 0) dfs(i, v++);
	cout << (v - 1) << endl;

	return 0;
}

Submission Info

Judge Result