bzoj2049: [Sdoi2008]Cave 洞穴勘測 lct裸題
阿新 • • 發佈:2018-05-30
its ase lct bzoj ble ons result else if ios
題意:三種操作一種摧毀一條邊,一種鏈接一條邊,一種查詢兩個點是否聯通
題解:lct的link和cut即可
/************************************************************** Problem: 2049 User: walfy Language: C++ Result: Accepted Time:1896 ms Memory:1508 kb ****************************************************************/ //#pragma comment(linker, "/stack:200000000") //#pragma GCC optimize("Ofast,no-stack-protector") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") //#pragma GCC optimize("unroll-loops") #include<bits/stdc++.h> #define fi first #define se second #define mp make_pair #define pb push_back #define pi acos(-1.0) #define ll long long #define vi vector<int> #define mod 1000000007 #define ld long double #define C 0.5772156649 #define ls l,m,rt<<1 #define rs m+1,r,rt<<1|1 #define pil pair<int,ll> #define pli pair<ll,int> #define pii pair<int,int> #define cd complex<double> #define ull unsigned long long #define base 1000000000000000000 #define fio ios::sync_with_stdio(false);cin.tie(0) using namespace std; const double eps=1e-6; const int N=10000+1,maxn=5000+10,inf=0x3f3f3f3f,INF=0x3f3f3f3f3f3f3f3f; struct LCT{ int fa[N],ch[N][2],rev[N],q[N]; bool isroot(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;} void pushup(int x){} void pushdown(int x) { if(rev[x]) { rev[x]=0;swap(ch[x][0],ch[x][1]); rev[ch[x][0]]^=1,rev[ch[x][1]]^=1; } } void Rotate(int x) { int y=fa[x],z=fa[y],l,r; if(ch[y][0]==x)l=0,r=l^1; else l=1,r=l^1; if(!isroot(y)) { if(ch[z][0]==y)ch[z][0]=x; else ch[z][1]=x; } fa[x]=z;fa[y]=x;fa[ch[x][r]]=y; ch[y][l]=ch[x][r];ch[x][r]=y; pushup(y);pushup(x); } void splay(int x) { int top=1;q[top]=x; for(int i=x;!isroot(i);i=fa[i])q[++top]=fa[i]; for(int i=top;i;i--)pushdown(q[i]); while(!isroot(x)) { int y=fa[x],z=fa[y]; if(!isroot(y)) { if((ch[y][0]==x)^(ch[z][0]==y))Rotate(x); else Rotate(y); } Rotate(x); } } void access(int x){for(int y=0;x;y=x,x=fa[x])splay(x),ch[x][1]=y,pushup(x);} void makeroot(int x){access(x),splay(x),rev[x]^=1;} int findroot(int x){access(x),splay(x);while(ch[x][0])x=ch[x][0];return x;} void split(int x,int y){makeroot(x),access(y),splay(y);} void cut(int x,int y){split(x,y);if(ch[y][0]==x)ch[y][0]=0,fa[x]=0;} void link(int x,int y){makeroot(x),fa[x]=y;} }lct; char s[N]; int main() { int n,m; scanf("%d%d",&n,&m); while(m--) { char op[10]; int x,y; scanf("%s%d%d",op,&x,&y); if(op[0]=='Q') { int fx=lct.findroot(x),fy=lct.findroot(y); if(fx!=fy)puts("No"); else puts("Yes"); } else if(op[0]=='C') { int fx=lct.findroot(x),fy=lct.findroot(y); if(fx!=fy)lct.link(x,y); } else if(op[0]=='D') { int fx=lct.findroot(x),fy=lct.findroot(y); if(fx==fy)lct.cut(x,y); } } return 0; } /******************** 200 5 Query 123 127 Connect 123 127 Query 123 127 Destroy 127 123 Query 123 127 ********************/
bzoj2049: [Sdoi2008]Cave 洞穴勘測 lct裸題