[HIHO1184]连通性二·边的双连通分量（双连通分量）

/*
━━━━━┒ギリギリ♂ eye！
┓┏┓┏┓┃キリキリ♂ mind！
┛┗┛┗┛┃＼○／
┓┏┓┏┓┃ /
┛┗┛┗┛┃ノ)
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┃┃┃┃┃┃
┻┻┻┻┻┻
*/
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>
using namespace std;
#define fr first
#define sc second
#define cl clear
#define BUG puts("here!!!")
#define W(a) while(a--)
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%lld", &a)
#define Rs(a) scanf("%s", a)
#define Cin(a) cin >> a
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "w", stdout)
#define Rep(i, len) for(int i = 0; i < (len); i++)
#define For(i, a, len) for(int i = (a); i < (len); i++)
#define Cls(a) memset((a), 0, sizeof(a))
#define Clr(a, x) memset((a), (x), sizeof(a))
#define Full(a) memset((a), 0x7f7f, sizeof(a))
#define lrt rt << 1
#define rrt rt << 1 | 1
#define pi 3.14159265359
#define RT return
#define lowbit(x) x & (-x)
#define onenum(x) __builtin_popcount(x)
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
typedef pair<int, int> pii;
typedef pair<string, int> psi;
typedef pair<LL, LL> pll;
typedef map<string, int> msi;
typedef vector<int> vi;
typedef vector<LL> vl;
typedef vector<vl> vvl;
typedef vector<bool> vb;

const int maxn = 50020;
const int maxm = 500100;
typedef struct Edge {
int u, v;
int next, i;
bool cut;
Edge() {}
Edge(int uu, int vv, int ii) : u(uu), v(vv), i(ii) {}
}Edge;

Edge edge[maxm];
int head[maxn], ecnt;
int n, m;
int dfn[maxn];
int low[maxn];
bool vis[maxn];
bool cut[maxn];
vi bridge;
int st[maxn], top;
int belong[maxn], bcnt;
vi tmp;
int ret;

void init() {
Clr(head, -1); Cls(low); Cls(dfn);
Cls(vis); Cls(cut); Cls(st); ret = 0;
bcnt = 1; top = 0; ecnt = 0; bridge.cl();
}

void adde(int uu, int vv, int ii) {
edge[ecnt] = Edge(uu, vv, ii);
edge[ecnt].cut = 0;
edge[ecnt].next = head[uu];
head[uu] = ecnt++;
}

void tarjan(int u, int d, int p) {
low[u] = dfn[u] = d;
st[++top] = u;
vis[u] = 1;
for(int i = head[u]; ~i; i=edge[i].next) {
int v = edge[i].v;
int id = edge[i].i;
if(p == id) continue;
if(!dfn[v]) {
tarjan(v, d+1, id);
low[u] = min(low[u], low[v]);
if(low[v] > dfn[u]) {
bridge.pb(i);
edge[i].cut = edge[i^1].cut = 1;
}
}
else low[u] = min(low[u], dfn[v]);
}
if(low[u] == dfn[u]) {
tmp.cl();
int v;
bcnt = 0x7f7f7f;
do {
v = st[top--];
vis[v] = 0;
bcnt = min(bcnt, v);
tmp.pb(v);
}while(v != u);
Rep(i, tmp.size()) belong[tmp[i]] = bcnt;
ret++;
}
}

int main() {
// FRead();
int u, v;
while(~scanf("%d%d", &n, &m)) {
init();
For(i, 1, m+1) {
Rint(u); Rint(v);
adde(u, v, i);
adde(v, u, i);
}
For(i, 1, n+1) {
if(!dfn[i]) tarjan(i, 1, -1);
}
printf("%d\n", ret);
For(i, 1, n+1) printf("%d ", belong[i]);
printf("\n");
}
RT 0;
}