题目链接：http://hihocoder.com/problemset/problem/1184
题意裸，写个博客记下输出姿势。
1 /* 2 ━━━━━┒ギリギリ♂ eye！ 3 ┓┏┓┏┓┃キリキリ♂ mind！ 4 ┛┗┛┗┛┃＼○／ 5 ┓┏┓┏┓┃ / 6 ┛┗┛┗┛┃ノ) 7 ┓┏┓┏┓┃ 8 ┛┗┛┗┛┃ 9 ┓┏┓┏┓┃ 10 ┛┗┛┗┛┃ 11 ┓┏┓┏┓┃ 12 ┛┗┛┗┛┃ 13 ┓┏┓┏┓┃ 14 ┃┃┃┃┃┃ 15 ┻┻┻┻┻┻ 16 */ 17 #include <algorithm> 18 #include <iostream> 19 #include <iomanip> 20 #include <cstring> 21 #include <climits> 22 #include <complex> 23 #include <fstream> 24 #include <cassert> 25 #include <cstdio> 26 #include <bitset> 27 #include <vector> 28 #include <deque> 29 #include <queue> 30 #include <stack> 31 #include <ctime> 32 #include <set> 33 #include <map> 34 #include <cmath> 35 using namespace std; 36 #define fr first 37 #define sc second 38 #define cl clear 39 #define BUG puts("here!!!") 40 #define W(a) while(a--) 41 #define pb(a) push_back(a) 42 #define Rint(a) scanf("%d", &a) 43 #define Rll(a) scanf("%lld", &a) 44 #define Rs(a) scanf("%s", a) 45 #define Cin(a) cin >> a 46 #define FRead() freopen("in", "r", stdin) 47 #define FWrite() freopen("out", "w", stdout) 48 #define Rep(i, len) for(int i = 0; i < (len); i++) 49 #define For(i, a, len) for(int i = (a); i < (len); i++) 50 #define Cls(a) memset((a), 0, sizeof(a)) 51 #define Clr(a, x) memset((a), (x), sizeof(a)) 52 #define Full(a) memset((a), 0x7f7f, sizeof(a)) 53 #define lrt rt << 1 54 #define rrt rt << 1 | 1 55 #define pi 3.14159265359 56 #define RT return 57 #define lowbit(x) x & (-x) 58 #define onenum(x) __builtin_popcount(x) 59 typedef long long LL; 60 typedef long double LD; 61 typedef unsigned long long ULL; 62 typedef pair<int, int> pii; 63 typedef pair<string, int> psi; 64 typedef pair<LL, LL> pll; 65 typedef map<string, int> msi; 66 typedef vector<int> vi; 67 typedef vector<LL> vl; 68 typedef vector<vl> vvl; 69 typedef vector<bool> vb; 70 71 const int maxn = 50020; 72 const int maxm = 500100; 73 typedef struct Edge { 74 int u, v; 75 int next, i; 76 bool cut; 77 Edge() {} 78 Edge(int uu, int vv, int ii) : u(uu), v(vv), i(ii) {} 79 }Edge; 80 81 Edge edge[maxm]; 82 int head[maxn], ecnt; 83 int n, m; 84 int dfn[maxn]; 85 int low[maxn]; 86 bool vis[maxn]; 87 bool cut[maxn]; 88 vi bridge; 89 int st[maxn], top; 90 int belong[maxn], bcnt; 91 vi tmp; 92 int ret; 93 94 void init() { 95 Clr(head, -1); Cls(low); Cls(dfn); 96 Cls(vis); Cls(cut); Cls(st); ret = 0; 97 bcnt = 1; top = 0; ecnt = 0; bridge.cl(); 98 } 99 100 void adde(int uu, int vv, int ii) { 101 edge[ecnt] = Edge(uu, vv, ii); 102 edge[ecnt].cut = 0; 103 edge[ecnt].next = head[uu]; 104 head[uu] = ecnt++; 105 } 106 107 108 void tarjan(int u, int d, int p) { 109 low[u] = dfn[u] = d; 110 st[++top] = u; 111 vis[u] = 1; 112 for(int i = head[u]; ~i; i=edge[i].next) { 113 int v = edge[i].v; 114 int id = edge[i].i; 115 if(p == id) continue; 116 if(!dfn[v]) { 117 tarjan(v, d+1, id); 118 low[u] = min(low[u], low[v]); 119 if(low[v] > dfn[u]) { 120 bridge.pb(i); 121 edge[i].cut = edge[i^1].cut = 1; 122 } 123 } 124 else low[u] = min(low[u], dfn[v]); 125 } 126 if(low[u] == dfn[u]) { 127 tmp.cl(); 128 int v; 129 bcnt = 0x7f7f7f; 130 do { 131 v = st[top--]; 132 vis[v] = 0; 133 bcnt = min(bcnt, v); 134 tmp.pb(v); 135 }while(v != u); 136 Rep(i, tmp.size()) belong[tmp[i]] = bcnt; 137 ret++; 138 } 139 } 140 141 int main() { 142 // FRead(); 143 int u, v; 144 while(~scanf("%d%d", &n, &m)) { 145 init(); 146 For(i, 1, m+1) { 147 Rint(u); Rint(v); 148 adde(u, v, i); 149 adde(v, u, i); 150 } 151 For(i, 1, n+1) { 152 if(!dfn[i]) tarjan(i, 1, -1); 153 } 154 printf("%d ", ret); 155 For(i, 1, n+1) printf("%d ", belong[i]); 156 printf(" "); 157 } 158 RT 0; 159 }