一本通基础篇图论
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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 ",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 ",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 ",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 ",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 "); 63 else 64 printf("%d ",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(" ")) 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 ",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 ",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 ",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 ",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 "); 60 else 61 printf("%d ",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 ",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 ",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 ",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 "); 57 else 58 printf("No "); 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 ",i); 50 return 0; 51 } 52 merge(ta,tb); 53 } 54 printf("draw "); 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 ",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 ",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 ",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 ",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 ",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
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