1341 一笔画问题
1 #include <cstdio>
2 #include <algorithm>
3 #include <stack>
4 using namespace std;
5 const int MAXN = 110000,MAXM = 510000;
6 stack <int> stk;
7 int head[MAXN],ind[MAXN];
8 int to[MAXM],nxt[MAXM],idx[MAXM];
9 int cnt,n,m;
10 void add(int x,int y,int i)
11 {
12 nxt[++cnt] = head[x];
13 to[cnt] = y;
14 head[x] = cnt;
15 idx[cnt] = i;
16 }
17 void dete(int x,int y)
18 {
19 if (head[x] == y)
20 {
21 head[x] = nxt[y];
22 return;
23 }
24 for (int i = head[x];i;i = nxt[i])
25 if (nxt[i] == y)
26 {
27 nxt[i] = nxt[y];
28 return;
29 }
30 }
31 void dfs(int x)
32 {
33 for (int i = head[x];i;i = head[x])//注意i=head[x];
34 {
35 head[x] = nxt[i];
36 dete(to[i],i ^ 1);
37 dfs(to[i]);
38 }
39 stk.push(x);
40 }
41 int main()
42 {
43 cnt = 1;
44 scanf("%d%d",&n,&m);
45 int ta,tb;
46 for (int i = 1;i <= m;i++)
47 {
48 scanf("%d%d",&ta,&tb);
49 add(ta,tb,i);
50 add(tb,ta,i);
51 ind[ta]++;
52 ind[tb]++;
53 }
54 bool flg = false;
55 for (int i = 1;i <= n;i++)
56 if (ind[i] & 1)
57 {
58 dfs(i);
59 flg = true;
60 break;
61 }
62 if (flg == false)
63 dfs(1);
64 while (!stk.empty())
65 {
66 printf("%d ",stk.top());
67 stk.pop();
68 }
69 return 0;
70 }
1374 铲雪车
1 #include <cstdio>
2 #include <cmath>
3 using namespace std;
4 typedef long long ll;
5 int main()
6 {
7 ll tx,ty,ux,uy,sx,sy;
8 scanf("%lld%lld",&sx,&sy);
9 double ans = 0;
10 while (scanf("%lld%lld%lld%lld",&tx,&ty,&ux,&uy) > 0)
11 ans += sqrt((ux - tx) * (ux - tx) + (uy - ty) * (uy - ty)) * 2;
12 ans = ans / 1000 / 20;
13 ll h = (ll)ans;
14 ll m = (ll)((ans - h) * 60 + 0.5);
15 printf("%lld:%02lld\n",h,m);
16 return 0;
17 }
1375 骑马修栅栏
1 #include <cstdio>
2 #include <algorithm>
3 #include <stack>
4 using namespace std;
5 stack <int> stk;
6 int m,n;
7 int ind[1200],mp[1200][1200];
8 void dfs(int x)
9 {
10 for (int i = 1;i <= n;i++)
11 if (mp[x][i])
12 {
13 mp[x][i]--;
14 mp[i][x]--;
15 dfs(i);
16 }
17 stk.push(x);
18 }
19 int main()
20 {
21 scanf("%d",&m);
22 int ta,tb;
23 for (int i = 1;i <= m;i++)
24 {
25 scanf("%d%d",&ta,&tb);
26 n = max(n,ta);
27 n = max(n,tb);
28 mp[ta][tb]++;
29 mp[tb][ta]++;
30 ind[ta]++;
31 ind[tb]++;
32 }
33 int tp = 1;
34 for (int i = 1;i <= n;i++)
35 if (ind[i] % 2)
36 {
37 tp = i;
38 break;
39 }
40 dfs(tp);
41 while (!stk.empty())
42 {
43 printf("%d\n",stk.top());
44 stk.pop();
45 }
46 return 0;
47 }
1342最短路径问题
1343牛的旅行
1 #include <cstdio>
2 #include <cmath>
3 #include <algorithm>s
4 using namespace std;
5 double sqr(double x)
6 {
7 return x * x;
8 }
9 double mp[200][200],l[200];
10 int x[200],y[200];
11 int n;
12 int main()
13 {
14 scanf("%d",&n);
15 for (int i = 1;i <= n;i++) scanf("%d%d",&x[i],&y[i]);
16 int tmp;
17 for (int i = 1;i <= n;i++)
18 for (int j = 1;j <= n;j++)
19 {
20 scanf("%1d",&tmp);
21 if (tmp == 0 && i != j) mp[i][j] = 2e9;
22 else mp[i][j] = sqrt(sqr(x[i] - x[j]) + sqr(y[i] - y[j]));
23 }
24 for (int k = 1;k <= n;k++)
25 for (int i = 1;i <= n;i++)
26 for (int j = 1;j <= n;j++)
27 mp[i][j] = min(mp[i][j],mp[i][k] + mp[k][j]);
28 double res = 2e9,ans = 0;
29
30 for (int i = 1;i <= n;i++)
31 for (int j = 1;j <= n;j++)
32 if (mp[i][j] < 2e9) l[i] = max(l[i],mp[i][j]);
33 for (int i = 1;i <= n;i++) ans = max(ans,l[i]);
34 for (int i = 1;i <= n;i++)
35 for (int j = 1;j <= n;j++)
36 if (mp[i][j] >= 2e9) res = min(res,l[i] + l[j] + sqrt(sqr(x[i] - x[j]) + sqr(y[i] - y[j])));
37 printf("%.6lf\n",max(res,ans));
38 return 0;
39 }
1344最小花费
1 #include <cstdio>
2 using namespace std;
3 double f[2100][2100],dis[2100];
4 int n,m,s,t;
5 bool vis[2100];
6 int main()
7 {
8 scanf("%d%d",&n,&m);
9 int tx,ty;
10 double tz;
11 for (int i = 1;i <= m;i++)
12 {
13 scanf("%d%d%lf",&tx,&ty,&tz);
14 f[tx][ty] = (100.0 - tz) / 100.0;
15 f[ty][tx] = f[tx][ty];
16 }
17 scanf("%d%d",&s,&t);
18 for (int i = 1;i <= n;i++)
19 dis[i] = 0.0;
20 dis[s] = 1.0;
21 for (int i = 2;i <= n;i++)
22 {
23 double maxn = 0.0;
24 int loc = 0;
25 for (int j = 1;j <= n;j++)
26 if (!vis[j] && dis[j] > maxn)
27 {
28 maxn = dis[j];
29 loc = j;
30 }
31 if (loc == 0)
32 break;
33 vis[loc] = true;
34 for (int j = 1;j <= n;j++)
35 if (!vis[j] && dis[loc] * f[loc][j] > dis[j])
36 dis[j] = dis[loc] * f[loc][j];
37 }
38 printf("%.8lf",100.0 / dis[t]);
39 return 0;
40 }
1345香甜的黄油
1 #include<cstdio>
2 #include<algorithm>
3 #include<queue>
4 using namespace std;
5 const int MAXN = 810,MAXM = 3100,inf = 1000000000;
6 int head[MAXN],dis[MAXN],to[MAXM],val[MAXM],nxt[MAXM],s[MAXN],cnt,c,n,m,ans;
7 bool vis[MAXN];
8 struct pot
9 {
10 int x,dis;
11 pot (int _x = 0,int _dis = 0) : x(_x),dis(_dis) {}
12 friend bool operator < (pot a,pot b)
13 {
14 return a.dis > b.dis;
15 }
16 };
17 priority_queue <pot> que;
18 void add(int x,int y,int v)
19 {
20 nxt[++cnt] = head[x];
21 to[cnt] = y;
22 head[x] = cnt;
23 val[cnt] = v;
24 }
25 void dijkstra(int sta)
26 {
27 for (int i = 1; i <= n;i++)
28 dis[i] = inf;
29 for (int i = 1;i <= n;i++)
30 vis[i] = false;
31 que.push(pot(sta,0));
32 dis[sta] = 0;
33 while (!que.empty())
34 {
35 pot now = que.top();
36 que.pop();
37 if (vis[now.x])
38 continue;
39 vis[now.x] = true;
40 for (int i = head[now.x];i;i = nxt[i])
41 {
42 if (dis[to[i]] > dis[now.x] + val[i])
43 {
44 dis[to[i]] = dis[now.x] + val[i];
45 que.push(pot(to[i],dis[to[i]]));
46 }
47 }
48 }
49 }
50 int main()
51 {
52 scanf("%d%d%d",&c,&n,&m);
53 for (int i = 1;i <= c;i++)
54 scanf("%d",&s[i]);
55 int tu,tv,tw;
56 for (int i = 1;i <= m;i++)
57 {
58 scanf("%d%d%d",&tu,&tv,&tw);
59 add(tu,tv,tw);
60 add(tv,tu,tw);
61 }
62 ans = inf;
63 for (int i = 1;i <= n;i++)
64 {
65 int sum = 0;
66 dijkstra(i);
67 for (int j = 1;j <= c;j++)
68 sum += dis[s[j]];
69 ans = min(ans,sum);
70 }
71 printf("%d\n",ans);
72 return 0;
73 }
1376信使
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 #include <queue>
5 using namespace std;
6 const int MAXN = 110,MAXM = 11000;
7 int head[MAXN],dis[MAXN],vis[MAXN],to[MAXM],nxt[MAXM],val[MAXM];
8 bool inq[MAXN];
9 int n,m,cnt;
10 void add(int x,int y,int v)
11 {
12 nxt[++cnt] = head[x];
13 to[cnt] = y;
14 head[x] = cnt;
15 val[cnt] = v;
16 }
17 bool SPFA(int s)
18 {
19 dis[s] = 0;
20 vis[s] = 1;
21 queue<int> q;
22 q.push(s);
23 inq[s] = true;
24 while(!q.empty())
25 {
26 int t = q.front();
27 q.pop();
28 inq[t] = false;
29 for(int i = head[t];i;i = nxt[i])
30 {
31 if(dis[to[i]] > dis[t] + val[i])
32 {
33 dis[to[i]] = dis[t] + val[i];
34 if(!inq[to[i]])
35 {
36 inq[to[i]] = 1;
37 vis[to[i]]++;
38 if(vis[to[i]] >= n) return true;
39 q.push(to[i]);
40 }
41 }
42 }
43 }
44 return false;
45 }
46 int main()
47 {
48 memset(dis,0x1f,sizeof(dis));
49 scanf("%d%d",&n,&m);
50 int tx,ty,tv;
51 for (int i = 1;i <= m;i++)
52 {
53 scanf("%d%d%d",&tx,&ty,&tv);
54 add(tx,ty,tv);
55 add(ty,tx,tv);
56 }
57 SPFA(1);
58 int maxn = 0;
59 for (int i = 1;i <= n;i++)
60 maxn = max(maxn,dis[i]);
61 if (maxn == dis[0])
62 printf("-1\n");
63 else
64 printf("%d\n",maxn);
65 return 0;
66 }
1377最优乘车
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 using namespace std;
5 int mp[510][510],vec[510],n,m;
6 char str[5100];
7 int main()
8 {
9 scanf("%d%d",&m,&n);
10 gets(str);
11 memset(mp,0x1f,sizeof(mp));
12 for (int i = 1;i <= m;i++)
13 {
14 gets(str);
15 int tmp = 0,cnt = 0;
16 for (int i = 0;str[i] != 0;i++)
17 if (str[i] >= '0' && str[i] <= '9')
18 tmp = tmp * 10 + str[i] - '0';
19 else if (str[i] == ' ')
20 {
21 vec[++cnt] = tmp;
22 tmp = 0;
23 }
24 if (tmp != 0)
25 vec[++cnt] = tmp;
26 for(int j = 1;j <= cnt;j++)
27 for(int k = j + 1;k <= cnt;k++)
28 mp[vec[j]][vec[k]] = 1;
29 }
30 for (int k = 1;k <= n;k++)
31 for (int i = 1;i <= n;i++)
32 for (int j = 1;j <= n;j++)
33 mp[i][j] = min(mp[i][j],mp[i][k] + mp[k][j]);
34 // for (int i = 1;i <= n;i++,printf("\n"))
35 // for (int j = 1;j <= n;j++)
36 // printf("%d ",mp[i][j]);
37 if (mp[1][n] >= 100000)
38 printf("NO");
39 else
40 printf("%d\n",mp[1][n] - 1);
41 return 0;
42 }
1378最短路径
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 #include <queue>
5 using namespace std;
6 const int MAXN = 110;
7 int dis[MAXN],vis[MAXN],mp[MAXN][MAXN];
8 bool inq[MAXN];
9 int n,s;
10 bool SPFA(int s)
11 {
12 dis[s] = 0;
13 vis[s] = 1;
14 queue<int> q;
15 q.push(s);
16 inq[s] = true;
17 while(!q.empty())
18 {
19 int t = q.front();
20 q.pop();
21 inq[t] = false;
22 for (int i = 1;i <= n;i++)
23 {
24 if(dis[i] > dis[t] + mp[t][i])
25 {
26 dis[i] = dis[t] + mp[t][i];
27 if(!inq[i])
28 {
29 inq[i] = 1;
30 vis[i]++;
31 if(vis[i] >= n) return true;
32 q.push(i);
33 }
34 }
35 }
36 }
37 return false;
38 }
39 int solve(char * str)
40 {
41 int ans = 0,f = 1;
42 if (str[0] == '-' && str[1] == 0)
43 return dis[0];
44 if (str[0] == '-')
45 f = -1;
46 for (int i = (f == 1 ? 0 : 1);str[i] != 0;i++)
47 ans = ans * 10 + str[i] - '0';
48 return ans * f;
49 }
50 int main()
51 {
52 memset(dis,0x1f,sizeof(dis));
53 memset(mp,0x1f,sizeof(mp));
54 scanf("%d%d",&n,&s);
55 int tx,ty,tv;
56 char str[10];
57 for (int i = 1;i <= n;i++)
58 for (int j = 1;j <= n;j++)
59 {
60 scanf("%s",str);
61 mp[i][j] = solve(str);
62 }
63 SPFA(s);
64 for (int i = 1;i <= n;i++)
65 if (i != s)
66 printf("(%d -> %d) = %d\n",s,i,dis[i]);
67 return 0;
68 }
1379热浪
1 #include <cstdio>
2 #include <queue>
3 #include <cstring>
4 using namespace std;
5 const int MAXN = 3000,MAXM = 14000;
6 struct pot
7 {
8 int x,dis;
9 pot(int _x = 0,int _dis = 0) :x(_x),dis(_dis){}
10 friend bool operator < (pot a,pot b)
11 {
12 return a.dis > b.dis;
13 }
14 };
15 priority_queue <pot> que;
16 bool vis[MAXN];
17 int head[MAXN],dis[MAXN];
18 int to[MAXM],nxt[MAXM],val[MAXM];
19 int cnt,n,m,s,t;
20 void add(int x,int y,int v)
21 {
22 nxt[++cnt] = head[x];
23 to[cnt] = y;
24 val[cnt] = v;
25 head[x] = cnt;
26 }
27 void dij(int s)
28 {
29 while (!que.empty()) que.pop();
30 que.push(pot(s,0));
31 memset(dis,0x1f,sizeof(dis));
32 dis[s] = 0;
33 while (!que.empty())
34 {
35 int u = que.top().x;
36 que.pop();
37 if (vis[u]) continue;
38 vis[u] = true;
39 for (int i = head[u];i;i = nxt[i])
40 {
41 if (dis[to[i]] > dis[u] + val[i])
42 {
43 dis[to[i]] = dis[u] + val[i];
44 que.push(pot(to[i],dis[to[i]]));
45 }
46 }
47 }
48 }
49 int main()
50 {
51 scanf("%d%d%d%d",&n,&m,&s,&t);
52 int tx,ty,tv;
53 for (int i = 1;i <= m;i++)
54 {
55 scanf("%d%d%d",&tx,&ty,&tv);
56 add(tx,ty,tv);
57 add(ty,tx,tv);
58 }
59 dij(s);
60 printf("%d\n",dis[t]);
61 return 0;
62 }
1380分糖果
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 #include <queue>
5 using namespace std;
6 const int MAXN = 110000,MAXM = 2100000;
7 int head[MAXN],dis[MAXN],to[MAXM],nxt[MAXM];
8 int n,m,p,c,cnt;
9 void add(int x,int y)
10 {
11 nxt[++cnt] = head[x];
12 to[cnt] = y;
13 head[x] = cnt;
14 }
15 bool BFS(int s)
16 {
17 dis[s] = 1;
18 queue<int> q;
19 q.push(s);
20 while(!q.empty())
21 {
22 int t = q.front();
23 q.pop();
24 for(int i = head[t];i;i = nxt[i])
25 {
26 if(dis[to[i]] == -1)
27 {
28 dis[to[i]] = dis[t] + 1;
29 q.push(to[i]);
30 }
31 }
32 }
33 return false;
34 }
35 int main()
36 {
37 memset(dis,-1,sizeof(dis));
38 scanf("%d%d%d%d",&n,&p,&c,&m);
39 int tx,ty;
40 for (int i = 1;i <= p;i++)
41 {
42 scanf("%d%d",&tx,&ty);
43 add(tx,ty);
44 add(ty,tx);
45 }
46 BFS(c);
47 int maxn = 0;
48 for (int i = 1;i <= n;i++)
49 maxn = max(maxn,dis[i]);
50 printf("%d\n",maxn + m);
51 return 0;
52 }
1381城市路
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 #include <queue>
5 using namespace std;
6 const int MAXN = 2100,MAXM = 21000;
7 int head[MAXN],dis[MAXN],vis[MAXN],to[MAXM],nxt[MAXM],val[MAXM];
8 bool inq[MAXN];
9 int n,m,cnt;
10 void add(int x,int y,int v)
11 {
12 nxt[++cnt] = head[x];
13 to[cnt] = y;
14 head[x] = cnt;
15 val[cnt] = v;
16 }
17 bool SPFA(int s)
18 {
19 dis[s] = 0;
20 vis[s] = 1;
21 queue<int> q;
22 q.push(s);
23 inq[s] = true;
24 while(!q.empty())
25 {
26 int t = q.front();
27 q.pop();
28 inq[t] = false;
29 for(int i = head[t];i;i = nxt[i])
30 {
31 if(dis[to[i]] > dis[t] + val[i])
32 {
33 dis[to[i]] = dis[t] + val[i];
34 if(!inq[to[i]])
35 {
36 inq[to[i]] = 1;
37 vis[to[i]]++;
38 if(vis[to[i]] >= n) return true;
39 q.push(to[i]);
40 }
41 }
42 }
43 }
44 return false;
45 }
46 int main()
47 {
48 memset(dis,0x1f,sizeof(dis));
49 scanf("%d%d",&n,&m);
50 int tx,ty,tv;
51 for (int i = 1;i <= m;i++)
52 {
53 scanf("%d%d%d",&tx,&ty,&tv);
54 add(tx,ty,tv);
55 add(ty,tx,tv);
56 }
57 SPFA(1);
58 if (dis[n] == dis[0])
59 printf("-1\n");
60 else
61 printf("%d\n",dis[n]);
62 return 0;
63 }
1382最短路
1 #include <cstdio>
2 #include <algorithm>
3 #include <cstring>
4 #include <queue>
5 using namespace std;
6 const int MAXN = 110000,MAXM = 1100000;
7 int head[MAXN],dis[MAXN],vis[MAXN],to[MAXM],nxt[MAXM],val[MAXM];
8 bool inq[MAXN];
9 int n,m,cnt;
10 void add(int x,int y,int v)
11 {
12 nxt[++cnt] = head[x];
13 to[cnt] = y;
14 head[x] = cnt;
15 val[cnt] = v;
16 }
17 bool SPFA(int s)
18 {
19 dis[s] = 0;
20 vis[s] = 1;
21 queue<int> q;
22 q.push(s);
23 inq[s] = true;
24 while(!q.empty())
25 {
26 int t = q.front();
27 q.pop();
28 inq[t] = false;
29 for(int i = head[t];i;i = nxt[i])
30 {
31 if(dis[to[i]] > dis[t] + val[i])
32 {
33 dis[to[i]] = dis[t] + val[i];
34 if(!inq[to[i]])
35 {
36 inq[to[i]] = 1;
37 vis[to[i]]++;
38 if(vis[to[i]] >= n) return true;
39 q.push(to[i]);
40 }
41 }
42 }
43 }
44 return false;
45 }
46 int main()
47 {
48 memset(dis,0x1f,sizeof(dis));
49 scanf("%d%d",&n,&m);
50 int tx,ty,tv;
51 for (int i = 1;i <= m;i++)
52 {
53 scanf("%d%d%d",&tx,&ty,&tv);
54 add(tx,ty,tv);
55 add(ty,tx,tv);
56 }
57 SPFA(1);
58 printf("%d\n",dis[n]);
59 return 0;
60 }
1383刻录光盘
1 #include <cstdio>
2 #include <stack>
3 using namespace std;
4 const int MAXN = 210,MAXM = 41000;
5 int head[MAXN],dfn[MAXN],low[MAXN],nxt[MAXM],to[MAXM],blg[MAXN],ind[MAXN];
6 bool ins[MAXN];
7 int cnt,n,tim,scc,ans;
8 stack <int> stk;
9 void add(int x,int y)
10 {
11 nxt[++cnt] = head[x];
12 to[cnt] = y;
13 head[x] = cnt;
14 }
15 void tarjan(int x)
16 {
17 dfn[x] = low[x] = ++tim;
18 stk.push(x);
19 ins[x] = true;
20 for (int i = head[x];i;i = nxt[i])
21 {
22 if (!dfn[to[i]])
23 {
24 tarjan(to[i]);
25 low[x] = min(low[x],low[to[i]]);
26 }else if (ins[to[i]])
27 low[x] = min(low[x],dfn[to[i]]);
28 }
29 if (low[x] == dfn[x])
30 {
31 ++scc;
32 int tmp = 0;
33 while (tmp != x)
34 {
35 tmp = stk.top();
36 stk.pop();
37 ins[tmp] = false;
38 blg[tmp] = scc;
39 }
40 }
41 }
42 int main()
43 {
44 scanf("%d",&n);
45 for (int i = 1;i <= n;i++)
46 {
47 int tx = 1;
48 for (;;)
49 {
50 scanf("%d",&tx);
51 if (tx == 0)
52 break;
53 add(i,tx);
54 }
55 }
56 for (int i = 1;i <= n;i++)
57 if (dfn[i] == 0)
58 tarjan(i);
59 for (int i = 1;i <= n;i++)
60 for (int o = head[i];o;o = nxt[o])
61 if (blg[i] != blg[to[o]])
62 ind[blg[to[o]]]++;
63 for (int i = 1;i <= scc;i++)
64 if (ind[i] == 0)
65 ans++;
66 printf("%d\n",ans);
67 }
1384珍珠
1 #include<bits/stdc++.h>
2 using namespace std;
3 const int MAXN = 200;
4 int a[MAXN][MAXN],b[MAXN][MAXN],cnt1[MAXN],cnt2[MAXN],n,m;
5 int main()
6 {
7 scanf("%d%d",&n,&m);
8 int tx,ty;
9 for (int i = 1;i <= m;i++)
10 {
11 scanf("%d%d",&tx,&ty);
12 a[tx][ty] = 1;
13 b[ty][tx] = 1;
14 }
15 for (int k = 1;k <= n;k++)
16 for (int i = 1;i <= n;i++)
17 for (int j = 1;j <= n;j++)
18 if (k != i && k != j && i != j)
19 {
20 a[i][j] |= a[i][k] && a[k][j];
21 b[i][j] |= b[i][k] && b[k][j];
22 }
23 for (int i = 1;i <= n;i++)
24 for (int j = 1;j <= n;j++)
25 if (i != j){
26 if (a[i][j]) cnt1[i]++;
27 if (b[i][j]) cnt2[i]++;
28 }
29 int ans=0;
30 for (int i=1;i<=n;i++)
31 if (cnt1[i] >= (n + 1) / 2 || cnt2[i] >= (n + 1) / 2)
32 ans++;
33 printf("%d\n",ans);
34 return 0;
35 }
1346亲戚
1 #include <cstdio>
2 using namespace std;
3 int fa[21000],siz[21000];
4 int n,m,q;
5 int read()
6 {
7 int x=0,f=1;char ch=getchar();
8 while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
9 while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
10 return x*f;
11 }
12 void pre_dsu(int n)
13 {
14 for (int i = 1;i <= n;i++)
15 fa[i] = i,siz[i] = 1;
16 }
17 int getfa(int u)
18 {
19 if (fa[u] == u) return u;
20 return fa[u] = getfa(fa[u]);
21 }
22 void merge(int u,int v)
23 {
24 int s1 = getfa(u),s2 = getfa(v);
25 if(s1 == s2) return;
26 if (siz[s1] < siz[s2])
27 {
28 fa[s1] = s2;
29 }else if (siz[s1] > siz[s2])
30 {
31 fa[s2] = s1;
32 }else
33 {
34 fa[s1] = s2;
35 siz[s1]++;
36 }
37 }
38 int main()
39 {
40 scanf("%d%d",&n,&m);
41 pre_dsu(n);
42 int ta,tb;
43 for (int i = 1;i <= m;i++)
44 {
45 ta = read();
46 tb = read();
47 if(getfa(ta) != getfa(tb))
48 merge(ta,tb);
49 }
50 scanf("%d",&q);
51 for (int i = 1;i <= q;i++)
52 {
53 ta = read();
54 tb = read();
55 if (getfa(ta) == getfa(tb))
56 printf("Yes\n");
57 else
58 printf("No\n");
59 }
60 return 0;
61 }
1347格子游戏
1 #include <cstdio>
2 using namespace std;
3 int fa[41000],siz[41000];
4 int n,m;
5 void pre_dsu(int n)
6 {
7 for (int i = 1;i <= n;i++)
8 fa[i] = i,siz[i] = 1;
9 }
10 int getfa(int u)
11 {
12 if (fa[u] == u) return u;
13 return fa[u] = getfa(fa[u]);
14 }
15 void merge(int u,int v)
16 {
17 int s1 = getfa(u),s2 = getfa(v);
18 if(s1 == s2) return;
19 if (siz[s1] < siz[s2])
20 {
21 fa[s1] = s2;
22 siz[s2] += siz[s1];
23 }else
24 {
25 fa[s2] = s1;
26 siz[s1] += siz[s2];
27 }
28 }
29 int num(int x,int y)
30 {
31 return (x - 1) * n + y;
32 }
33 int main()
34 {
35 scanf("%d%d",&n,&m);
36 pre_dsu(n * n);
37 int tx,ty,ta,tb;
38 char s[10];
39 for (int i = 1;i <= m;i++)
40 {
41 scanf("%d%d%s",&tx,&ty,s);
42 ta = num(tx,ty);
43 if (s[0] == 'D')
44 tb = num(tx + 1,ty);
45 else
46 tb = num(tx,ty + 1);
47 if (getfa(ta) == getfa(tb))
48 {
49 printf("%d\n",i);
50 return 0;
51 }
52 merge(ta,tb);
53 }
54 printf("draw\n");
55 return 0;
56 }
1385团伙
1 #include <cstdio>
2 using namespace std;
3 int fa[2100],siz[2100];
4 bool vis[2100];
5 int n,m,cnt;
6 void pre_dsu(int n)
7 {
8 for (int i = 1;i <= n;i++)
9 fa[i] = i,siz[i] = 1;
10 }
11 int getfa(int u)
12 {
13 if (fa[u] == u) return u;
14 return fa[u] = getfa(fa[u]);
15 }
16 void merge(int u,int v)
17 {
18 int s1 = getfa(u),s2 = getfa(v);
19 if(s1 == s2) return;
20 if (siz[s1] < siz[s2])
21 {
22 fa[s1] = s2;
23 siz[s2] += siz[s1];
24 }else
25 {
26 fa[s2] = s1;
27 siz[s1] += siz[s2];
28 }
29 }
30 int main()
31 {
32 scanf("%d%d",&n,&m);
33 pre_dsu(2 * n);
34 int tp,tx,ty;
35 for (int i = 1;i <= m;i++)
36 {
37 scanf("%d%d%d",&tp,&tx,&ty);
38 if (tp == 0)
39 {
40 merge(tx,ty);
41 }else
42 {
43 merge(tx,ty + n);
44 merge(tx + n,ty);
45 }
46 }
47 for (int i = 1;i <= n;i++)
48 if (vis[getfa(i)] == false)
49 {
50 vis[getfa(i)] = true;
51 cnt++;
52 }
53 printf("%d\n",cnt);
54 return 0;
55 }
1386打击犯罪
1 #include <cstdio>
2 using namespace std;
3 int fa[1100],siz[1100];
4 int n,m,cnt,a[1100][1100];
5 void pre_dsu(int n)
6 {
7 for (int i = 1;i <= n;i++)
8 fa[i] = i,siz[i] = 1;
9 }
10 int getfa(int u)
11 {
12 if (fa[u] == u) return u;
13 return fa[u] = getfa(fa[u]);
14 }
15 void merge(int u,int v)
16 {
17 int s1 = getfa(u),s2 = getfa(v);
18 if(s1 == s2) return;
19 if (siz[s1] < siz[s2])
20 {
21 fa[s1] = s2;
22 siz[s2] += siz[s1];
23 }else
24 {
25 fa[s2] = s1;
26 siz[s1] += siz[s2];
27 }
28 }
29 int main()
30 {
31 scanf("%d",&n);
32 pre_dsu(n);
33 for (int i = 1;i <= n;i++)
34 {
35 scanf("%d",&a[i][0]);
36 for (int j = 1;j <= a[i][0];j++)
37 scanf("%d",&a[i][j]);
38 }
39 for (int i = n;i >= 1;i--)
40 {
41 for (int j = 1;j <= a[i][0];j++)
42 if(a[i][j] > i)
43 {
44 merge(i,a[i][j]);
45 if (siz[getfa(i)] > n / 2 || siz[getfa(a[i][j])] > n / 2)
46 {
47 printf("%d\n",i);
48 return 0;
49 }
50 }
51 }
52 }
1387搭配购买
1 #include <cstdio>
2 #include <algorithm>
3 using namespace std;
4 int fa[11000],siz[11000],f[11000],c[11000],d[11000],cst[11000],val[11000];
5 int n,m,w,cnt,ans;
6 void pre_dsu(int n)
7 {
8 for (int i = 1;i <= n;i++)
9 fa[i] = i,siz[i] = 1;
10 }
11 int getfa(int u)
12 {
13 if (fa[u] == u) return u;
14 return fa[u] = getfa(fa[u]);
15 }
16 void merge(int u,int v)
17 {
18 int s1 = getfa(u),s2 = getfa(v);
19 if(s1 == s2) return;
20 if (siz[s1] < siz[s2])
21 {
22 fa[s1] = s2;
23 siz[s2] += siz[s1];
24 c[s2] += c[s1];
25 d[s2] += d[s1];
26 }else
27 {
28 fa[s2] = s1;
29 siz[s1] += siz[s2];
30 c[s1] += c[s2];
31 d[s1] += d[s2];
32 }
33 }
34 int main()
35 {
36 scanf("%d%d%d",&n,&m,&w);
37 pre_dsu(n);
38 for (int i = 1;i <= n;i++)
39 scanf("%d%d",&c[i],&d[i]);
40 int ta,tb;
41 for (int i = 1;i <= m;i++)
42 {
43 scanf("%d%d",&ta,&tb);
44 merge(ta,tb);
45 }
46 for (int i = 1;i <= n;i++)
47 if (fa[i] == i)
48 {
49 cnt++;
50 cst[cnt] = c[i];
51 val[cnt] = d[i];
52 }
53 for (int i = 1;i <= cnt;i++)
54 for (int j = w;j >= cst[i];j--)
55 f[j] = max(f[j],f[j - cst[i]] + val[i]);
56 for (int i = 0;i <= w;i++)
57 ans = max(ans,f[i]);
58 printf("%d\n",ans);
59 }
1388家谱
1 #include <cstdio>
2 #include <algorithm>
3 #include <string>
4 #include <map>
5 #include <iostream>
6 using namespace std;
7 map <string,int> mp;
8 int fa[51000];
9 int cnt;
10 string nam[51000];
11 void pre_dsu(int n)
12 {
13 for (int i = 1;i <= n;i++)
14 fa[i] = i;
15 }
16 int getfa(int u)
17 {
18 if (fa[u] == u) return u;
19 return fa[u] = getfa(fa[u]);
20 }
21 int main()
22 {
23 pre_dsu(50000);
24 string s;
25 int f;
26 for (;;)
27 {
28 cin >> s;
29 if (mp[s.substr(1)] == 0)
30 {
31 mp[s.substr(1)] = ++cnt;
32 nam[cnt] = s.substr(1);
33 }
34 if (s[0] == '#')
35 {
36 f = mp[s.substr(1)];
37 }else if (s[0] == '+')
38 {
39 fa[mp[s.substr(1)]] = f;
40 }else if (s[0] == '?')
41 {
42 cout << s.substr(1) << " " << nam[getfa(mp[s.substr(1)])] << endl;
43 }else
44 {
45 return 0;
46 }
47 }
48 }
1389亲戚
1 #include <cstdio>
2 using namespace std;
3 int fa[110000],siz[110000];
4 int n,m;
5 void pre_dsu(int n)
6 {
7 for (int i = 1;i <= n;i++)
8 fa[i] = i,siz[i] = 1;
9 }
10 int getfa(int u)
11 {
12 if (fa[u] == u) return u;
13 return fa[u] = getfa(fa[u]);
14 }
15 void merge(int u,int v)
16 {
17 int s1 = getfa(u),s2 = getfa(v);
18 if(s1 == s2) return;
19 if (siz[s1] < siz[s2])
20 {
21 fa[s1] = s2;
22 siz[s2] += siz[s1];
23 }else
24 {
25 fa[s2] = s1;
26 siz[s1] += siz[s2];
27 }
28 }
29 int main()
30 {
31 scanf("%d%d",&n,&m);
32 pre_dsu(n);
33 int ta,tb;
34 char s[10];
35 for (int i = 1;i <= m;i++)
36 {
37 scanf("%s",s);
38 if (s[0] == 'M')
39 {
40 scanf("%d%d",&ta,&tb);
41 merge(ta,tb);
42 }else
43 {
44 scanf("%d",&ta);
45 printf("%d\n",siz[getfa(ta)]);
46 }
47 }
48 return 0;
49 }
1390食物链
比较难，带权并查集，可以忽略。
1 #include <cstdio>
2 using namespace std;
3 int fa[51000],num[51000];
4 int n,k,cnt;
5 void pre_dsu(int n)
6 {
7 for (int i = 1;i <= n;i++)
8 fa[i] = i;
9 }
10 int getfa(int u)
11 {
12 if (fa[u] == u) return u;
13 int f = fa[u];
14 fa[u] = getfa(fa[u]);
15 num[u] = (num[f] + num[u]) % 3;
16 return fa[u];
17 }
18 int main()
19 {
20 scanf("%d%d",&n,&k);
21 pre_dsu(n);
22 int td,tx,ty,ta,tb;
23 for (int i = 1;i <= k;i++)
24 {
25 scanf("%d%d%d",&td,&tx,&ty);
26 if (tx > n || ty > n)
27 {
28 cnt++;
29 continue;
30 }
31 ta = getfa(tx);
32 tb = getfa(ty);
33 if (ta == tb)
34 {
35 if (td == 1 && num[tx] != num[ty])
36 {
37 cnt++;
38 continue;
39 }else if (td == 2 && num[tx] != (num[ty] + 1) % 3)
40 {
41 cnt++;
42 continue;
43 }
44 }else
45 {
46 if (td == 1)
47 {
48 fa[ta] = tb;
49 num[ta] = (3 + num[ty] - num[tx]) % 3;
50 }else
51 {
52 fa[ta] = tb;
53 num[ta] = (3 + num[ty] - num[tx] + 1) % 3;
54 }
55 }
56 }
57 printf("%d\n",cnt);
58 return 0;
59 }
1348城市公交网建设问题
1349最优布线问题
1350最短网络
1351家谱树
1391局域网
1392繁忙的都市
1393联络员
1394连接格点
1352奖金
1395烦人的幻灯片
1396病毒
来源：https://www.cnblogs.com/iat14/p/12210160.html