【bzoj4012】[HNOI2015]开店 动态树分治+二分查找

#include <cstdio>
#include <vector>
#include <algorithm>
#define N 150010
using namespace std;
typedef long long ll;
struct data
{
	int val;
	ll dis , sum;
	data() {}
	data(int a , ll b , ll c) {val = a , dis = b , sum = c;}
	bool operator<(const data &a)const {return val == a.val ? dis == a.dis ? sum < a.sum : dis < a.dis : val < a.val;}
};
vector<data> va[N] , vb[N];
int a[N] , head[N] , to[N << 1] , len[N << 1] , next[N << 1] , cnt , pos[N] , log[N << 1] , tot;
int si[N] , mx[N] , sum , root , vis[N] , fa[N];
ll deep[N] , md[20][N << 1];
void add(int x , int y , int z)
{
	to[++cnt] = y , len[cnt] = z , next[cnt] = head[x] , head[x] = cnt;
}
void dfs(int x , int fa)
{
	int i;
	pos[x] = ++tot , md[0][tot] = deep[x];
	for(i = head[x] ; i ; i = next[i])
		if(to[i] != fa)
			deep[to[i]] = deep[x] + len[i] , dfs(to[i] , x) , md[0][++tot] = deep[x];
}
ll calc(int x , int y)
{
	ll t = deep[x] + deep[y];
	x = pos[x] , y = pos[y];
	if(x > y) swap(x , y);
	int k = log[y - x + 1];
	return t - 2 * min(md[k][x] , md[k][y - (1 << k) + 1]);
}
void getroot(int x , int fa)
{
	int i;
	si[x] = 1 , mx[x] = 0;
	for(i = head[x] ; i ; i = next[i])
		if(!vis[to[i]] && to[i] != fa)
			getroot(to[i] , x) , si[x] += si[to[i]] , mx[x] = max(mx[x] , si[to[i]]);
	mx[x] = max(mx[x] , sum - si[x]);
	if(mx[x] < mx[root]) root = x;
}
void solve(int x)
{
	int i;
	vis[x] = 1;
	for(i = head[x] ; i ; i = next[i])
		if(!vis[to[i]])
			sum = si[to[i]] , root = 0 , getroot(to[i] , 0) , fa[root] = x , solve(root);
}
ll query(int x , int p)
{
	int i , t;
	ll ans = 0;
	for(i = x ; i ; i = fa[i])
	{
		t = lower_bound(va[i].begin() , va[i].end() , data(p , 0 , 0)) - va[i].begin() - 1;
		ans += va[i][t].sum + t * calc(i , x);
	}
	for(i = x ; fa[i] ; i = fa[i])
	{
		t = lower_bound(vb[i].begin() , vb[i].end() , data(p , 0 , 0)) - vb[i].begin() - 1;
		ans -= vb[i][t].sum + t * calc(fa[i] , x);
	}
	return ans;
}
int main()
{
	int n , m , k , i , j , x , y , z;
	ll last = 0;
	scanf("%d%d%d" , &n , &m , &k);
	for(i = 1 ; i <= n ; i ++ ) scanf("%d" , &a[i]);
	for(i = 1 ; i < n ; i ++ ) scanf("%d%d%d" , &x , &y , &z) , add(x , y , z) , add(y , x , z);
	dfs(1 , 0);
	for(i = 2 ; i <= tot ; i ++ ) log[i] = log[i >> 1] + 1;
	for(i = 1 ; (1 << i) <= tot ; i ++ )
		for(j = 1 ; j <= tot - (1 << i) + 1 ; j ++ )
			md[i][j] = min(md[i - 1][j] , md[i - 1][j + (1 << (i - 1))]);
	mx[0] = 1 << 30 , sum = n , getroot(1 , 0) , solve(root);
	for(i = 1 ; i <= n ; i ++ )
		for(j = i ; j ; j = fa[j])
			va[j].push_back(data(a[i] , calc(i , j) , 0)) , vb[j].push_back(data(a[i] , calc(i , fa[j]) , 0));
	for(i = 1 ; i <= n ; i ++ )
	{
		va[i].push_back(data(-1 , 0 , 0)) , va[i].push_back(data(1 << 30 , 0 , 0));
		vb[i].push_back(data(-1 , 0 , 0)) , vb[i].push_back(data(1 << 30 , 0 , 0));
		sort(va[i].begin() , va[i].end()) , sort(vb[i].begin() , vb[i].end());
		for(j = 1 ; j < (int)va[i].size() ; j ++ ) va[i][j].sum = va[i][j - 1].sum + va[i][j].dis;
		for(j = 1 ; j < (int)vb[i].size() ; j ++ ) vb[i][j].sum = vb[i][j - 1].sum + vb[i][j].dis;
	}
	while(m -- )
	{
		scanf("%d%d%d" , &x , &y , &z) , y = (y + last) % k , z = (z + last) % k;
		if(y > z) swap(y , z);
		printf("%lld\n" , last = query(x , z + 1) - query(x , y));
	}
	return 0;
}