2243: [SDOI2011]染色
Time Limit: 20 Sec Memory Limit: 512 MBSubmit: 5020 Solved: 1872
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Description
给定一棵有n个节点的无根树和m个操作,操作有2类:
1、将节点a到节点b路径上所有点都染成颜色c;
2、询问节点a到节点b路径上的颜色段数量(连续相同颜色被认为是同一段),如“112221”由3段组成:“11”、“222”和“1”。
请你写一个程序依次完成这m个操作。
Input
第一行包含2个整数n和m,分别表示节点数和操作数;
第二行包含n个正整数表示n个节点的初始颜色
下面 行每行包含两个整数x和y,表示x和y之间有一条无向边。
下面 行每行描述一个操作:
“C a b c”表示这是一个染色操作,把节点a到节点b路径上所有点(包括a和b)都染成颜色c;
“Q a b”表示这是一个询问操作,询问节点a到节点b(包括a和b)路径上的颜色段数量。
Output
对于每个询问操作,输出一行答案。
Sample Input
6 5
2 2 1 2 1 1
1 2
1 3
2 4
2 5
2 6
Q 3 5
C 2 1 1
Q 3 5
C 5 1 2
Q 3 5
2 2 1 2 1 1
1 2
1 3
2 4
2 5
2 6
Q 3 5
C 2 1 1
Q 3 5
C 5 1 2
Q 3 5
Sample Output
3
1
2
1
2
HINT
数N<=10^5,操作数M<=10^5,所有的颜色C为整数且在[0, 10^9]之间。
Source
题解:
树链剖分处理一下连接点之间的颜色是否相同即可。。。
线段树中记录 左右颜色,分成段数即可。。。
其实LCT做这道题也是不错的呦!!!(两个程序都挂上吧。。。)
对比:
LCT:
9088 kb |
17756 ms |
树链剖分:
29944 kb | 8652 ms |
树链剖分:
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define MAXN 100010 4 struct node 5 { 6 int begin,end,next; 7 }edge[MAXN*2]; 8 struct NODE 9 { 10 int left,right,lc,rc,color,tag,sum; 11 }tree[MAXN*5]; 12 int cnt,Head[MAXN],size[MAXN],deep[MAXN],P[MAXN][17],pos[MAXN],belong[MAXN],c[MAXN],SIZE,n; 13 bool vis[MAXN]; 14 void addedge(int bb,int ee) 15 { 16 edge[++cnt].begin=bb;edge[cnt].end=ee;edge[cnt].next=Head[bb];Head[bb]=cnt; 17 } 18 void addedge1(int bb,int ee) 19 { 20 addedge(bb,ee);addedge(ee,bb); 21 } 22 int read() 23 { 24 int s=0,fh=1;char ch=getchar(); 25 while(ch<'0'||ch>'9'){if(ch=='-')fh=-1;ch=getchar();} 26 while(ch>='0'&&ch<='9'){s=s*10+(ch-'0');ch=getchar();} 27 return s*fh; 28 } 29 void dfs1(int u) 30 { 31 int i,v; 32 size[u]=1;vis[u]=true; 33 for(i=Head[u];i!=-1;i=edge[i].next) 34 { 35 v=edge[i].end; 36 if(vis[v]==false) 37 { 38 deep[v]=deep[u]+1; 39 P[v][0]=u; 40 dfs1(v); 41 size[u]+=size[v]; 42 } 43 } 44 } 45 void Ycl() 46 { 47 int i,j; 48 for(j=1;(1<<j)<=n;j++) 49 { 50 for(i=1;i<=n;i++) 51 { 52 if(P[i][j-1]!=-1)P[i][j]=P[P[i][j-1]][j-1]; 53 } 54 } 55 } 56 void dfs2(int u,int chain) 57 { 58 int k=0,i,v; 59 pos[u]=++SIZE;belong[u]=chain; 60 for(i=Head[u];i!=-1;i=edge[i].next) 61 { 62 v=edge[i].end; 63 if(deep[v]>deep[u]&&size[v]>size[k])k=v; 64 } 65 if(k==0)return; 66 dfs2(k,chain); 67 for(i=Head[u];i!=-1;i=edge[i].next) 68 { 69 v=edge[i].end; 70 if(deep[v]>deep[u]&&v!=k)dfs2(v,v); 71 } 72 } 73 int LCA(int x,int y) 74 { 75 int i,j; 76 if(deep[x]<deep[y])swap(x,y); 77 for(i=0;(1<<i)<=deep[x];i++);i--; 78 for(j=i;j>=0;j--)if(deep[x]-(1<<j)>=deep[y])x=P[x][j]; 79 if(x==y)return x; 80 for(j=i;j>=0;j--) 81 { 82 if(P[x][j]!=-1&&P[x][j]!=P[y][j]) 83 { 84 x=P[x][j]; 85 y=P[y][j]; 86 } 87 } 88 return P[x][0]; 89 } 90 void Pushup(int k) 91 { 92 int l=k*2,r=k*2+1; 93 tree[k].lc=tree[l].lc; 94 tree[k].rc=tree[r].rc; 95 if(tree[l].rc==tree[r].lc)tree[k].sum=tree[l].sum+tree[r].sum-1; 96 else tree[k].sum=tree[l].sum+tree[r].sum; 97 } 98 void Pushdown(int k) 99 { 100 int l=k*2,r=k*2+1; 101 if(tree[k].tag!=-1) 102 { 103 tree[l].tag=tree[k].tag; 104 tree[r].tag=tree[k].tag; 105 tree[l].lc=tree[l].rc=tree[l].color=tree[k].tag; 106 tree[r].lc=tree[r].rc=tree[r].color=tree[k].tag; 107 tree[l].sum=tree[r].sum=1; 108 tree[k].tag=-1; 109 } 110 } 111 void Build(int k,int l,int r) 112 { 113 tree[k].left=l;tree[k].right=r;tree[k].tag=-1; 114 if(l==r)return; 115 int mid=(l+r)/2; 116 Build(k*2,l,mid);Build(k*2+1,mid+1,r); 117 } 118 void Change(int k,int l,int r,int C) 119 { 120 if(l<=tree[k].left&&tree[k].right<=r){tree[k].lc=tree[k].rc=tree[k].color=tree[k].tag=C;tree[k].sum=1;return;} 121 Pushdown(k); 122 int mid=(tree[k].left+tree[k].right)/2; 123 if(r<=mid)Change(k*2,l,r,C); 124 else if(l>mid)Change(k*2+1,l,r,C); 125 else {Change(k*2,l,mid,C);Change(k*2+1,mid+1,r,C);} 126 Pushup(k); 127 } 128 void Solve_change(int x,int f,int C) 129 { 130 while(belong[x]!=belong[f]) 131 { 132 Change(1,pos[belong[x]],pos[x],C); 133 x=P[belong[x]][0]; 134 } 135 Change(1,pos[f],pos[x],C); 136 } 137 int Query_sum(int k,int l,int r) 138 { 139 if(l<=tree[k].left&&tree[k].right<=r)return tree[k].sum; 140 Pushdown(k); 141 int mid=(tree[k].left+tree[k].right)/2; 142 if(r<=mid)return Query_sum(k*2,l,r); 143 else if(l>mid)return Query_sum(k*2+1,l,r); 144 //else return Query_sum(k*2,l,mid)+Query_sum(k*2+1,mid+1,r); 145 else 146 { 147 if(tree[k*2].rc==tree[k*2+1].lc)return Query_sum(k*2,l,mid)+Query_sum(k*2+1,mid+1,r)-1; 148 else return Query_sum(k*2,l,mid)+Query_sum(k*2+1,mid+1,r); 149 } 150 //Pushup(k); 151 } 152 int get_color(int k,int lr) 153 { 154 if(tree[k].left==tree[k].right)return tree[k].color; 155 Pushdown(k); 156 int mid=(tree[k].left+tree[k].right)/2; 157 if(lr<=mid)return get_color(k*2,lr); 158 else if(lr>mid)return get_color(k*2+1,lr); 159 } 160 int Solve_sum(int x,int f) 161 { 162 int sum=0; 163 while(belong[x]!=belong[f]) 164 { 165 sum+=Query_sum(1,pos[belong[x]],pos[x]); 166 if(get_color(1,pos[belong[x]])==get_color(1,pos[P[belong[x]][0]]))sum--; 167 x=P[belong[x]][0]; 168 } 169 sum+=Query_sum(1,pos[f],pos[x]); 170 return sum; 171 } 172 int main() 173 { 174 int m,i,bb,ee,A,B,C,lca; 175 char zs[2]; 176 n=read();m=read(); 177 for(i=1;i<=n;i++)c[i]=read(); 178 memset(Head,-1,sizeof(Head));cnt=1; 179 for(i=1;i<n;i++){bb=read();ee=read();addedge1(bb,ee);} 180 memset(P,-1,sizeof(P));SIZE=0; 181 dfs1(1);Ycl(); 182 dfs2(1,1); 183 Build(1,1,n); 184 for(i=1;i<=n;i++)Change(1,pos[i],pos[i],c[i]); 185 for(i=1;i<=m;i++) 186 { 187 scanf("%s",zs); 188 if(zs[0]=='C') 189 { 190 A=read();B=read();C=read(); 191 lca=LCA(A,B); 192 Solve_change(A,lca,C);Solve_change(B,lca,C); 193 } 194 else 195 { 196 A=read();B=read(); 197 lca=LCA(A,B); 198 printf("%d ",Solve_sum(A,lca)+Solve_sum(B,lca)-1); 199 } 200 } 201 fclose(stdin); 202 fclose(stdout); 203 return 0; 204 }
LCT(代码略丑):
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define LL long long 4 #define MAXN 100010 5 #define INF 1e9 6 struct node 7 { 8 LL left,right,color,tag1,lc,rc,sum; 9 }tree[MAXN]; 10 LL rev[MAXN],father[MAXN],Stack[MAXN]; 11 LL read() 12 { 13 LL s=0,fh=1;char ch=getchar(); 14 while(ch<'0'||ch>'9'){if(ch=='-')fh=-1;ch=getchar();} 15 while(ch>='0'&&ch<='9'){s=s*10+(ch-'0');ch=getchar();} 16 return s*fh; 17 } 18 LL isroot(LL x) 19 { 20 return tree[father[x]].left!=x&&tree[father[x]].right!=x; 21 } 22 void pushdown(LL x) 23 { 24 LL l=tree[x].left,r=tree[x].right; 25 if(rev[x]!=0) 26 { 27 rev[x]^=1;rev[l]^=1;rev[r]^=1; 28 swap(tree[x].left,tree[x].right); 29 swap(tree[x].lc,tree[x].rc); 30 //tree[x].lc=tree[r].lc;tree[x].rc=tree[l].rc; 31 //swap(tree[l].color,tree[r].color); 32 //swap(tree[l].sum,tree[r].sum); 33 } 34 if(tree[x].tag1!=-1) 35 { 36 //tree[l].lc=tree[l].rc=tree[x].tag1; 37 //tree[r].lc=tree[r].rc=tree[x].tag1; 38 /*tree[l].color=*/tree[x].color=tree[x].lc=tree[x].rc=tree[x].tag1; 39 tree[l].tag1=tree[r].tag1=tree[x].tag1; 40 tree[x].sum=1; 41 tree[x].tag1=-1; 42 } 43 } 44 void pushup(LL x) 45 { 46 LL l=tree[x].left,r=tree[x].right; 47 //if(tree[l].rc==tree[r].lc) 48 //{ 49 if(l!=0)pushdown(l); 50 if(r!=0)pushdown(r); 51 //if(l!=0)lr+=tree[l].sum; 52 //if(r!=0)lr+=tree[r].sum; 53 tree[x].sum=tree[l].sum+tree[r].sum+1; 54 if(l!=0&&tree[l].rc==tree[x].color)tree[x].sum--; 55 if(r!=0&&tree[r].lc==tree[x].color)tree[x].sum--; 56 //tree[x].sum=lr; 57 tree[x].lc=tree[x].rc=tree[x].color; 58 if(l!=0)tree[x].lc=tree[l].lc; 59 if(r!=0)tree[x].rc=tree[r].rc; 60 //tree[x].sum=tree[l].sum+tree[r].sum-1; 61 //tree[x].lc=tree[l].lc; 62 //tree[x].rc=tree[r].rc; 63 //} 64 //else 65 //{ 66 //tree[x].sum=tree[l].sum+tree[r].sum; 67 //tree[x].lc=tree[l].lc; 68 //tree[x].rc=tree[r].rc; 69 //if(l!=0)lr+=tree[l].sum,tree[x].lc=tree[l].lc; 70 //if(r!=0)lr+=tree[r].sum,tree[x].rc=tree[r].rc; 71 //if(lr!=0)tree[x].sum=lr+1; 72 //} 73 } 74 void rotate(LL x) 75 { 76 LL y=father[x],z=father[y]; 77 if(!isroot(y)) 78 { 79 if(tree[z].left==y)tree[z].left=x; 80 else tree[z].right=x; 81 } 82 if(tree[y].left==x) 83 { 84 father[x]=z;father[y]=x;tree[y].left=tree[x].right;tree[x].right=y;father[tree[y].left]=y; 85 } 86 else 87 { 88 father[x]=z;father[y]=x;tree[y].right=tree[x].left;tree[x].left=y;father[tree[y].right]=y; 89 } 90 pushup(y);pushup(x); 91 } 92 void splay(LL x) 93 { 94 LL top=0,i,y,z;Stack[++top]=x; 95 for(i=x;!isroot(i);i=father[i])Stack[++top]=father[i]; 96 for(i=top;i>=1;i--)pushdown(Stack[i]); 97 while(!isroot(x)) 98 { 99 y=father[x];z=father[y]; 100 if(!isroot(y)) 101 { 102 if((tree[y].left==x)^(tree[z].left==y))rotate(x); 103 else rotate(y); 104 } 105 rotate(x); 106 } 107 } 108 void access(LL x) 109 { 110 LL last=0; 111 while(x!=0) 112 { 113 splay(x); 114 tree[x].right=last;pushup(x); 115 last=x;x=father[x]; 116 } 117 } 118 void makeroot(LL x) 119 { 120 access(x);splay(x);rev[x]^=1; 121 } 122 void link(LL u,LL v) 123 { 124 makeroot(u);father[u]=v;splay(u); 125 } 126 void cut(LL u,LL v) 127 { 128 makeroot(u);access(v);splay(v);father[u]=tree[v].left=0; 129 } 130 LL findroot(LL x) 131 { 132 access(x);splay(x); 133 while(tree[x].left!=0)x=tree[x].left; 134 return x; 135 } 136 int main() 137 { 138 LL i,x,y,n,m,a,b,c; 139 char fh[2]; 140 n=read();m=read(); 141 tree[0].lc=tree[0].rc=-INF; 142 for(i=1;i<=n;i++)tree[i].color=tree[i].lc=tree[i].rc=read(),tree[i].sum=1,tree[i].tag1=-1; 143 for(i=1;i<n;i++) 144 { 145 x=read();y=read(); 146 link(x,y); 147 } 148 for(i=1;i<=m;i++) 149 { 150 scanf(" %s",fh); 151 if(fh[0]=='C') 152 { 153 a=read();b=read();c=read(); 154 makeroot(a);access(b);splay(b); 155 tree[b].color=tree[b].lc=tree[b].rc=c;tree[b].tag1=c; 156 tree[b].sum=1; 157 } 158 else 159 { 160 a=read();b=read(); 161 makeroot(a);access(b);splay(b); 162 printf("%d ",tree[b].sum); 163 } 164 } 165 return 0; 166 }