B - The Suspects POJ - 1611

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 #include <iostream>
  5 #include <cmath>
  6 #include <assert.h>
  7 #include <vector>
  8 
  9 #define dbg(x) cout << #x << "=" << x << endl
 10 
 11 using namespace std;
 12 typedef long long LL;
 13 const int maxn = 30007;
 14 
 15 int fa[maxn];
 16 int n,m,ans,cnt;
 17 bool vis[maxn];
 18 int a[maxn];
 19 
 20 //vector <int> v;
 21 
 22 void init()
 23 {
 24     for(int i = 1; i <= n; i++) {
 25         fa[i] = i;
 26     }
 27 }
 28 
 29 int fid(int x)
 30 {
 31     int r = x;
 32     while(fa[r] != r) {
 33         r = fa[r];
 34     }
 35     int i,j;///路径压缩
 36     i = x;
 37     while(fa[i] != r) {
 38         j = fa[i];
 39         fa[i] =  r;
 40         i = j;
 41     }
 42     return r;
 43 }
 44 
 45 void join(int r1, int r2)///合并
 46 {
 47     int fidroot1 = fid(r1), fidroot2 = fid(r2);
 48     int root = min(fidroot1, fidroot2);
 49     if(fidroot1 != fidroot2) {
 50         fa[fidroot1] = root;
 51         fa[fidroot2] = root;
 52     }
 53 }
 54 
 55 template<class T>inline void read(T &res)
 56 {
 57     char c;T flag=1;
 58     while((c=getchar())<‘0‘||c>‘9‘)if(c==‘-‘)flag=-1;res=c-‘0‘;
 59     while((c=getchar())>=‘0‘&&c<=‘9‘)res=res*10+c-‘0‘;res*=flag;
 60 }
 61 
 62 namespace _buff {
 63     const size_t BUFF = 1 << 19;
 64     char ibuf[BUFF], *ib = ibuf, *ie = ibuf;
 65     char getc() {
 66         if (ib == ie) {
 67             ib = ibuf;
 68             ie = ibuf + fread(ibuf, 1, BUFF, stdin);
 69         }
 70         return ib == ie ? -1 : *ib++;
 71     }
 72 }
 73 
 74 int qread() {
 75     using namespace _buff;
 76     int ret = 0;
 77     bool pos = true;
 78     char c = getc();
 79     for (; (c < ‘0‘ || c > ‘9‘) && c != ‘-‘; c = getc()) {
 80         assert(~c);
 81     }
 82     if (c == ‘-‘) {
 83         pos = false;
 84         c = getc();
 85     }
 86     for (; c >= ‘0‘ && c <= ‘9‘; c = getc()) {
 87         ret = (ret << 3) + (ret << 1) + (c ^ 48);
 88     }
 89     return pos ? ret : -ret;
 90 }
 91 
 92 int main()
 93 {
 94     while(scanf("%d %d",&n, &m) && (n+m)) {
 95         int ans = 0;
 96         if(m == 0) {
 97             puts("1");
 98             continue;
 99         }
100         init();
101         //v.clear();
102         while(m--) {
103             int k;
104             scanf("%d",&k);
105             memset(a,0,sizeof(a));
106             for(int i = 1; i <= k; ++i) {
107                 scanf("%d",&a[i]);
108                 if(i == 1) continue;
109                 join(a[i], a[i-1]);
110             }
111         }
112         int pre = fid(0);
113         for(int i = 0; i < n; ++i) {
114             int now = fid(i);
115             //printf("fa[%d]:%d\n",i,now);
116             if(now == pre) {
117                 ans++;
118             }
119         }
120         cout << ans << endl;
121     }
122     return 0;
123 }