BZOJ 2002 动态树

 

动态树讲解：http://www.cnblogs.com/proverbs/archive/2013/01/04/2845053.html

 

贴代码混数~

 

View Code

  1 #include <iostream>

  2 #include <algorithm>

  3 #include <cstdlib>

  4 #include <cstring>

  5 #include <cstdio>

  6 

  7 #define N 420000

  8 

  9 using namespace std;

 10 

 11 int son[N][2],sum[N],fa[N],k[N];

 12 int n,m;

 13 

 14 inline void read()

 15 {

 16     scanf("%d",&n);

 17     for(int i=1;i<=n;i++)

 18     {

 19         scanf("%d",&k[i]);

 20         fa[i]=min(i+k[i],n+1);

 21     }

 22 }

 23 

 24 inline bool isroot(int x)

 25 {

 26     return son[fa[x]][0]!=x&&son[fa[x]][1]!=x;

 27 }

 28 

 29 inline void pushup(int x)

 30 {

 31     if(x) sum[x]=sum[son[x][0]]+sum[son[x][1]]+1;

 32 }

 33 

 34 inline void zig(int x)

 35 {

 36     int y=fa[x];

 37     if(son[x][1]) son[y][0]=son[x][1],fa[son[x][1]]=y;

 38     else son[y][0]=0;

 39     fa[x]=fa[y];

 40     if(son[fa[y]][0]==y) son[fa[y]][0]=x;

 41     else if(son[fa[y]][1]==y) son[fa[y]][1]=x;

 42     fa[y]=x; son[x][1]=y;

 43     pushup(y); pushup(x);

 44 }

 45 

 46 inline void zag(int x)

 47 {

 48     int y=fa[x];

 49     if(son[x][0]) son[y][1]=son[x][0],fa[son[x][0]]=y;

 50     else son[y][1]=0;

 51     fa[x]=fa[y];

 52     if(son[fa[y]][0]==y) son[fa[y]][0]=x;

 53     else if(son[fa[y]][1]==y) son[fa[y]][1]=x;

 54     fa[y]=x; son[x][0]=y;

 55     pushup(y); pushup(x);

 56 }

 57 

 58 inline void splay(int x)

 59 {

 60     while(!isroot(x))

 61     {

 62         int y=fa[x];

 63         if(isroot(y))

 64         {

 65             if(son[y][0]==x) zig(x);

 66             else zag(x);

 67         }

 68         else

 69         {

 70             if(son[fa[y]][0]==y)

 71             {

 72                 if(son[y][0]==x) zig(y);

 73                 else zag(x);

 74                 zig(x);

 75             }

 76             else

 77             {

 78                 if(son[y][0]==x) zig(x);

 79                 else zag(y);

 80                 zag(x);

 81             }

 82         }

 83     }

 84 }

 85 

 86 inline void access(int x)

 87 {

 88     for(int y=0;x;y=x,x=fa[x])

 89     {

 90         splay(x);

 91         son[x][1]=y;

 92     }

 93 }

 94 

 95 inline void cut(int x,int y)

 96 {

 97     access(x); splay(x);

 98     fa[son[x][0]]=0;

 99     son[x][0]=0;

100     fa[x]=min(x+y,n+1);

101     access(x);

102 }

103 

104 inline void change(int x)

105 {

106     access(x); splay(x);

107     printf("%d\n",sum[son[x][0]]);

108 }

109 

110 inline void go()

111 {

112     int x,y;

113     scanf("%d",&m);

114     while(m--)

115     {

116         scanf("%d",&x);

117         if(x==1)

118         {

119             scanf("%d",&x); x++;

120             change(x);

121         }

122         else

123         {

124             scanf("%d%d",&x,&y);x++;

125             cut(x,y);

126         }

127     }

128 }

129 

130 int main()

131 {

132     read(),go();

133     return 0;

134 }