【HDU】5296 Annoying problem【树链剖分+分类讨论】
传送门：【HDU】5296 Annoying problem
这题我是分类讨论做的，没想到多校题解的方法
my code:
#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std ;
typedef long long LL ;
#define clr(a,x) memset ( a , x , sizeof a )
#define ls ( o << 1 )
#define rs ( o << 1 | 1 )
#define lson ls , l , m
#define rson rs , m + 1 , r
#define root 1 , 1 , n
#define mid ( ( l + r ) >> 1 )
const int MAXN = 100005 ;
const int MAXE = 200005 ;
struct Edge {
int v , n ;
Edge () {}
Edge ( int v , int n ) : v ( v ) , n ( n ) {}
} ;
struct Node {
int u , v , c ;
} ;
Node node[MAXN] ;
Edge E[MAXE] ;
int H[MAXN] , cntE ;
int dep[MAXN] ;
int top[MAXN] ;
int siz[MAXN] ;
int son[MAXN] ;
int pre[MAXN] ;
int idx[MAXN] ;
int pos[MAXN] ;
int in[MAXN] , ou[MAXN] , dfs_clock ;
int tree_idx ;
int sum[MAXN] ;
int f[MAXN][18] ;
int vis[MAXN] ;
int lca[MAXN << 2] ;
int cnt[MAXN << 2] ;
int n , q ;
void init () {
cntE = 0 ;
tree_idx = 0 ;
dfs_clock = 0 ;
clr ( H , -1 ) ;
clr ( f , 0 ) ;
}
void addedge ( int u , int v ) {
E[cntE] = Edge ( v , H[u] ) ;
H[u] = cntE ++ ;
}
void dfs ( int u ) {
in[u] = ++ dfs_clock ;
siz[u] = 1 ;
son[u] = 0 ;
for ( int i = H[u] ; ~i ; i = E[i].n ) {
int v = E[i].v ;
if ( v == pre[u] ) continue ;
pre[v] = u ;
dep[v] = dep[u] + 1 ;
f[v][0] = u ;
for ( int j = 1 ; j < 18 ; ++ j ) {//这里比赛的时候和dfs(v)写反了，一直调不出来，不然比赛的时候就AC了……太弱
f[v][j] = f[f[v][j - 1]][j - 1] ;
}
dfs ( v ) ;
siz[u] += siz[v] ;
if ( siz[son[u]] < siz[v] ) son[u] = v ;
}
ou[u] = dfs_clock ;
}
void rebuild ( int u , int top_element ) {
top[u] = top_element ;
pos[u] = ++ tree_idx ;
if ( son[u] ) rebuild ( son[u] , top_element ) ;
for ( int i = H[u] ; ~i ; i = E[i].n ) {
int v = E[i].v ;
if ( v != pre[u] && v != son[u] ) rebuild ( v , v ) ;
}
}
int LCA ( int x , int y ) {
if ( !x && !y ) return 0 ;
if ( !x ) return y ;
if ( !y ) return x ;
if ( dep[x] < dep[y] ) swap ( x , y ) ;
for ( int i = 17 ; i >= 0 ; -- i ) {
if ( dep[x] - ( 1 << i ) >= dep[y] ) x = f[x][i] ;
}
if ( x == y ) return x ;
for ( int i = 17 ; i >= 0 ; -- i ) {
if ( f[x][i] != f[y][i] ) {
x = f[x][i] ;
y = f[y][i] ;
}
}
return f[x][0] ;
}
void update ( int x , int v , int o , int l , int r ) {
if ( l == r ) {
lca[o] = v ;
cnt[o] = v ? 1 : 0 ;
return ;
}
int m = mid ;
if ( x <= m ) update ( x , v , lson ) ;
else update ( x , v , rson ) ;
lca[o] = LCA ( lca[ls] , lca[rs] ) ;
cnt[o] = cnt[ls] + cnt[rs] ;
}
int query ( int L , int R , int o , int l , int r ) {
if ( L <= l && r <= R ) return lca[o] ;
int m = mid ;
if ( R <= m ) return query ( L , R , lson ) ;
if ( m < L ) return query ( L , R , rson ) ;
return LCA ( query ( L , R , lson ) , query ( L , R , rson ) ) ;
}
int query_cnt ( int L , int R , int o , int l , int r ) {
if ( L <= l && r <= R ) return cnt[o] ;
int m = mid ;
if ( R <= m ) return query_cnt ( L , R , lson ) ;
if ( m < L ) return query_cnt ( L , R , rson ) ;
return query_cnt ( L , R , lson ) + query_cnt ( L , R , rson ) ;
}
int Query ( int x , int y ) {
int res = 0 ;
while ( top[x] != top[y] ) {
if ( dep[top[x]] < dep[top[y]] ) swap ( x , y ) ;
res += sum[pos[x]] - sum[pos[top[x]] - 1] ;
x = pre[top[x]] ;
}
if ( x == y ) return res ;
if ( dep[x] > dep[y] ) swap ( x , y ) ;
res += sum[pos[y]] - sum[pos[x]] ;
return res ;
}
int jump ( int x ) {
for ( int i = 17 ; i >= 0 ; -- i ) {
if ( f[x][i] ) {
if ( !query_cnt ( in[f[x][i]] , ou[f[x][i]] , root ) ) x = f[x][i] ;
}
}
return f[x][0] ;
}
void solve () {
int op , x ;
init () ;
scanf ( "%d%d" , &n , &q ) ;
for ( int i = 1 ; i < n ; ++ i ) {
scanf ( "%d%d%d" , &node[i].u , &node[i].v , &node[i].c ) ;
addedge ( node[i].u , node[i].v ) ;
addedge ( node[i].v , node[i].u ) ;
}
dfs ( 1 ) ;
rebuild ( 1 , 1 ) ;
for ( int i = 1 ; i < n ; ++ i ) {
int u = node[i].u ;
int v = node[i].v ;
if ( dep[u] > dep[v] ) sum[pos[u]] = node[i].c ;
else sum[pos[v]] = node[i].c ;
}
for ( int i = 1 ; i <= n ; ++ i ) {
sum[i] += sum[i - 1] ;
}
clr ( lca , 0 ) ;
clr ( cnt , 0 ) ;
clr ( vis , 0 ) ;
int ans = 0 ;
while ( q -- ) {
scanf ( "%d%d" , &op , &x ) ;
if ( op == 1 ) {
if ( !vis[x] ) {
vis[x] = 1 ;
int lcatot = query ( 1 , n , root ) ;
// printf ( "-----%d %d\n" , lcatot , LCA ( x , lcatot ) ) ;
if ( LCA ( x , lcatot ) == x ) {
int num = query_cnt ( in[x] , ou[x] , root ) ;
if ( num ) ans += Query ( x , lcatot ) ;
} else {
if ( !query_cnt ( in[x] , ou[x] , root ) ) {
int y = jump ( x ) ;
// printf ( "%d\n" , y ) ;
// printf ( "cnt = %d\n" , query_cnt ( in[2] , ou[2] , root ) ) ;
ans += Query ( x , y ) ;
int z = query ( in[y] , ou[y] , root ) ;
if ( dep[lcatot] >= dep[y] ) ans += Query ( z , y ) ;
}
}
update ( in[x] , x , root ) ;
// printf ( "cnt[5] = %d\n" , query_cnt ( in[5] , in[5] , root ) ) ;
cnt[0] ++ ;
//printf ( "%d %d\n" , in[4] , ou[4] ) ;
//printf ( "in[%d] = %d\n" , 8 , in[8] ) ;
// printf ( "------------%d\n" , LCA ( 4 , 8 ) ) ;
}
} else {
if ( vis[x] ) {
vis[x] = 0 ;
update ( in[x] , 0 , root ) ;
cnt[0] -- ;
int lcatot = query ( 1 , n , root ) ;
if ( LCA ( x , lcatot ) == x ) {
int num = query_cnt ( in[x] , ou[x] , root ) ;
if ( num ) ans -= Query ( x , lcatot ) ;
} else {
// printf ( "%d\n" , query_cnt ( in[x] + 1 , ou[x] , root ) ) ;
if ( !query_cnt ( in[x] , ou[x] , root ) ) {
//printf ( "ok\n" ) ;
int y = jump ( x ) ;
ans -= Query ( x , y ) ;
int z = query ( in[y] , ou[y] , root ) ;
// printf ( "%d %d\n" , y , z ) ;
if ( dep[lcatot] >= dep[y] ) ans -= Query ( z , y ) ;
}
}
}
}
printf ( "%d\n" , ans ) ;
}
}
int main () {
int T ;
scanf ( "%d" , &T ) ;
for ( int i = 1 ; i <= T ; ++ i ) {
printf ( "Case #%d:\n" , i ) ;
solve () ;
}
return 0 ;
}