标签：中心 blank scanf .com 长度 int const top return
地址：http://www.lydsy.com/JudgeOnline/problem.php?id=2594
题目：
1 /************************************************************** 2 Problem: 2594 3 User: weeping 4 Language: C++ 5 Result: Accepted 6 Time:25656 ms 7 Memory:103836 kb 8 ****************************************************************/ 9 10 #include <bits/stdc++.h> 11 12 using namespace std; 13 namespace fastIO{ 14 #define BUF_SIZE 500000 15 bool IOerror=0; 16 inline char nc(){ 17 static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE; 18 if(p1==pend){ 19 p1=buf; 20 pend=buf+fread(buf,1,BUF_SIZE,stdin); 21 if(pend==p1){ 22 IOerror=1; 23 return -1; 24 } 25 }return *p1++; 26 } 27 inline bool blank(char ch){ 28 return ch==‘ ‘||ch==‘\n‘||ch==‘\r‘||ch==‘\t‘; 29 } 30 inline bool read(int &x){ 31 char ch; 32 while(blank(ch=nc())); 33 if(IOerror)return 0; 34 for(x=ch-‘0‘;(ch=nc())>=‘0‘&&ch<=‘9‘;x=x*10+ch-‘0‘); 35 return 1; 36 } 37 #undef BUF_SIZE 38 }; 39 40 using namespace fastIO; 41 42 struct node 43 { 44 int u,v,w,f; 45 node(){} 46 node(int x,int y,int z){u=x,v=y,w=z;} 47 }eg[1000007],qs[100007]; 48 int n,m,q,f[100007],vis[1000007],ans[100007]; 49 map<pair<int,int>,int>hs; 50 51 struct Link_Cut_Tree 52 { 53 static const int MAXN = 1200000 + 7; 54 55 int ch[MAXN][2], fa[MAXN], rev[MAXN], sz[MAXN], v[MAXN], mx[MAXN], id[MAXN]; 56 int sk[MAXN]; 57 58 bool isroot(int x) 59 { 60 return ch[fa[x]][0] != x && ch[fa[x]][1] != x; 61 } 62 63 void reverse(int x) 64 { 65 rev[x] ^= 1, swap(ch[x][0],ch[x][1]); 66 } 67 68 void update(int x) 69 { 70 int lc = ch[x][0], rc = ch[x][1]; 71 if(mx[lc]>mx[rc]) 72 mx[x]=mx[lc],id[x]=id[lc]; 73 else 74 mx[x]=mx[rc],id[x]=id[rc]; 75 if(v[x]>mx[x]) 76 mx[x]=v[x],id[x]=x; 77 } 78 79 void push_down(int x) 80 { 81 if(!rev[x]) return ; 82 if(ch[x][0]) reverse(ch[x][0]); 83 if(ch[x][1]) reverse(ch[x][1]); 84 rev[x]=0; 85 } 86 87 void rotate(int x) 88 { 89 int f = fa[x], gf = fa[f]; 90 int t1 = ( x != ch[f][0]), t2 = ( f != ch[gf][0]), tmp = ch[x][1^t1]; 91 if(!isroot(f)) ch[gf][0^t2] = x; 92 fa[tmp] = f, fa[x] = gf, ch[x][1^t1] = f, fa[f] = x, ch[f][0^t1] = tmp; 93 update(f); 94 } 95 96 void splay(int x) 97 { 98 int top = 0; 99 sk[++top] = x; 100 for(int i = x; !isroot(i); i = fa[i]) sk[++top] = fa[i]; 101 while(top) push_down(sk[top--]); 102 for(int f = fa[x], gf = fa[f]; !isroot(x); rotate(x), f = fa[x],gf = fa[f]) 103 if(!isroot(f)) 104 rotate((x==ch[f][0]) ^ (f==ch[gf][0]) ? x : f); 105 update(x); 106 } 107 108 void access(int x) 109 { 110 for(int p = 0; x; p = x, x = fa[x]) 111 splay(x), ch[x][1] = p, update(x); 112 } 113 114 void makeroot(int x) 115 { 116 access(x), splay(x), reverse(x); 117 } 118 119 int findroot(int x) 120 { 121 access(x), splay(x); 122 while(ch[x][0]) x = ch[x][0]; 123 return x; 124 } 125 void link(int x,int y) 126 { 127 makeroot(x), fa[x] = y; 128 } 129 130 void cut(int x,int y) 131 { 132 makeroot(x), access(y), splay(y); 133 if(ch[y][0] == x) ch[y][0] = fa[x] = 0; 134 update(y); 135 } 136 137 int go(int op,int x,int y,int hid) 138 { 139 if(x>y) swap(x,y); 140 if(op==1) 141 { 142 makeroot(x),access(y),splay(y); 143 return mx[y]; 144 } 145 if(findroot(x)!=findroot(y)) 146 link(x,hid+n),link(hid+n,y); 147 else 148 { 149 makeroot(x),access(y),splay(y); 150 if(mx[y]>eg[hid].w) 151 { 152 int pp=id[y]-n; 153 cut(eg[pp].u,pp+n),cut(eg[pp].v,pp+n); 154 link(x,hid+n),link(hid+n,y); 155 } 156 } 157 return 0; 158 } 159 void debug(void) 160 { 161 for(int i=1;i<=100;i++) 162 printf("%d %d %d %d %d %d %d\n",i,fa[i],ch[i][0],ch[i][1],rev[i],sz[i]); 163 } 164 }lct; 165 166 int tid[1000007]; 167 bool cmp(const int &ta,const int &tb) 168 { 169 return eg[ta].w<eg[tb].w; 170 } 171 int fd(int x) 172 { 173 return f[x]==x?x:f[x]=fd(f[x]); 174 } 175 void mintree(void) 176 { 177 for(int i=1;i<=n;i++) f[i]=i; 178 for(int i=1;i<=m;i++) tid[i]=i; 179 sort(tid+1,tid+1+m,cmp); 180 for(int i=1;i<=m;i++) 181 { 182 int p=tid[i]; 183 if(vis[p]) continue; 184 int fa=fd(eg[p].u),fb=fd(eg[p].v); 185 if(fa==fb) continue; 186 f[fa]=fb,lct.link(eg[p].u,p+n),lct.link(eg[p].v,p+n); 187 } 188 } 189 int main(void) 190 { 191 //freopen("in.acm","r",stdin); 192 read(n),read(m),read(q); 193 for(int i=0;i<=n;i++) lct.v[i]=-1; 194 for(int i=1,x,y,z;i<=m;i++) 195 { 196 read(x),read(y),read(z),eg[i]=node(x,y,z); 197 if(x>y)swap(x,y); 198 hs[make_pair(x,y)]=i; 199 lct.v[i+n]=lct.mx[i+n]=z,lct.id[i+n]=i+n; 200 } 201 for(int i=1,op,x,y;i<=q;i++) 202 { 203 read(op),read(x),read(y),qs[i]=node(op,x,y); 204 if(x>y)swap(x,y); 205 qs[i].f=hs[make_pair(x,y)]; 206 if(op==2) 207 vis[qs[i].f]=1; 208 } 209 mintree(); 210 for(int i=q;i;i--) 211 ans[i]=lct.go(qs[i].u,qs[i].v,qs[i].w,qs[i].f); 212 for(int i=1;i<=q;i++) 213 if(qs[i].u==1) 214 printf("%d\n",ans[i]); 215 return 0; 216 }
标签：中心 blank scanf .com 长度 int const top return
原文地址：http://www.cnblogs.com/weeping/p/7617818.html
