Connected Components?【Codeforces 920E】【补图的联通块的个数】

Educational Codeforces Round 37 (Rated for Div. 2) E

  怎么说呢，跟这道题是一样的，这道题就变得很模板了。

原题！！！

#include <iostream>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <limits>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#define lowbit(x) ( x&(-x) )
#define pi 3.141592653589793
#define e 2.718281828459045
#define INF 0x3f3f3f3f
#define eps 1e-9
#define HalF (l + r)>>1
#define lsn rt<<1
#define rsn rt<<1|1
#define Lson lsn, l, mid
#define Rson rsn, mid+1, r
#define QL Lson, ql, qr
#define QR Rson, ql, qr
#define myself rt, l, r
#define MP(a, b) make_pair(a, b)
using namespace std;
typedef unsigned long long ull;
typedef unsigned int uit;
typedef long long ll;
const int maxN = 2e5 + 7;
int N, M, head[maxN], cnt;
struct LIST
{
    int pre, nex;
    LIST(int a=0, int b=0):pre(a), nex(b) {}
}lst[maxN];
inline void Del(int id)
{
    lst[lst[id].pre].nex = lst[id].nex;
    lst[lst[id].nex].pre = lst[id].pre;
    lst[id] = LIST();
}
struct Eddge
{
    int nex, to;
    Eddge(int a=-1, int b=0):nex(a), to(b) {}
}edge[maxN<<1];
inline void addEddge(int u, int v)
{
    edge[cnt] = Eddge(head[u], v);
    head[u] = cnt++;
}
inline void _add(int u, int v) { addEddge(u, v); addEddge(v, u); }
bool vis[maxN] = {false};
int siz[maxN], KK = 0;
void bfs()
{
    int it;
    while(lst[0].nex != N + 1)
    {
        siz[++KK] = 1;
        it = lst[0].nex;
        Del(it);
        queue<int> Q;
        Q.push(it);
        int u, now, nex;
        while(!Q.empty())
        {
            u = Q.front(); Q.pop();
            for(int i=head[u], v; ~i; i=edge[i].nex)
            {
                v = edge[i].to;
                vis[v] = true;
            }
            now = lst[0].nex;
            while(now != N + 1)
            {
                nex = lst[now].nex;
                if(vis[now]) vis[now] = false;
                else
                {
                    Del(now);
                    Q.push(now);
                    siz[KK]++;
                }
                now = nex;
            }
        }
    }
}
inline void init()
{
    cnt = 0;
    for(int i=1; i<=N; i++)
    {
        head[i] = -1;
        lst[i] = LIST(i - 1, i + 1);
    }
    lst[0].nex = 1; lst[N + 1].pre = N;
}
int main()
{
    scanf("%d%d", &N, &M);
    init();
    for(int i=1, u, v; i<=M; i++)
    {
        scanf("%d%d", &u, &v);
        _add(u, v);
    }
    bfs();
    printf("%d\n", KK);
    sort(siz + 1, siz + KK + 1);
    for(int i=1; i<=KK; i++) printf("%d%c", siz[i], i == KK ? '\n' : ' ');
    return 0;
}