BZOJ 4012 [HNOI2015]开店 (区间修改 永久化标记 主席树)

讲得好啊
主席树区间修改了,每一次遇到整区间就打永久化标记(不下传,访问的时候沿路径上的标记算答案)然后$return$,那么每修改一次只会访问到$logn$个节点,再加上每个点要在树链上修改$logn$次,所以空间复杂度$O(nlog^2n)$,实测开$O(n*50)$能过…
各个sum都要开longlong啊,毁一生

CODE

#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
template<typename T>inline void read(T &num) {
	char ch; int flg = 1;
	while((ch=getchar())<'0'||ch>'9')if(ch=='-')flg=-flg;
	for(num=0;ch>='0'&&ch<='9';num=num*10+ch-'0',ch=getchar());
	num*=flg;
}
const int MAXN = 150005;
const int MAXNN = MAXN*50;
int n, q, A, fir[MAXN], cnt;
struct edge { int to, nxt, w; }e[MAXN<<1];
inline void add(int u, int v, int wt) {
	e[cnt] = (edge){ v, fir[u], wt }, fir[u] = cnt++;
	e[cnt] = (edge){ u, fir[v], wt }, fir[v] = cnt++;
}
struct node {
	int x, id;
	node() {}
	node(int xx, int ii):x(xx), id(ii){}
	inline bool operator <(const node &o)const {
		return x == o.x ? id < o.id : x < o.x;
	}
}a[MAXN];

LL sumE[MAXN], dis[MAXN], sumD[MAXN];
int son[MAXN], sz[MAXN], top[MAXN], tmr, dfn[MAXN], fa[MAXN];
void dfs(int u, int ff) {
	fa[u] = ff; sz[u] = 1;
	for(int i = fir[u], v; ~i; i = e[i].nxt)
		if((v=e[i].to) != ff) {
			dis[v] = dis[u] + e[i].w;
			dfs(v, u), sz[u] += sz[v];
			if(sz[v] > sz[son[u]]) son[u] = v;
		}
}
void dfs2(int u, int tp) {
	top[u] = tp; dfn[u] = ++tmr;
	sumE[tmr] = dis[u] - dis[fa[u]];
	if(son[u]) dfs2(son[u], tp);
	for(int i = fir[u], v; ~i; i = e[i].nxt)
		if((v=e[i].to) != fa[u] && v != son[u])
			dfs2(v, v);
}
int ch[MAXNN][2], tim[MAXNN], tot, rt[MAXN]; LL sum[MAXNN];

inline void Newnode(int i, int p) { ch[i][0] = ch[p][0], ch[i][1] = ch[p][1], sum[i] = sum[p], tim[i] = tim[p]; }

void modify(int &i, int l, int r, int L, int R) {
	Newnode(++tot, i);
	if(L == l && r == R) { ++tim[i = tot]; return; }
	sum[i = tot] += sumE[R] - sumE[L-1];
	int mid = (l + r) >> 1;
	if(R <= mid) modify(ch[i][0], l, mid, L, R);
	else if(L > mid) modify(ch[i][1], mid+1, r, L, R);
	else modify(ch[i][0], l, mid, L, mid), modify(ch[i][1], mid+1, r, mid+1, R);
}
inline void Modify(int &r, int x) { while(x) modify(r, 1, n, dfn[top[x]], dfn[x]), x = fa[top[x]]; }
LL query(int i, int l, int r, int L, int R) {
	LL res = (sumE[R] - sumE[L-1]) * tim[i];
	if(L == l && r == R) return res + sum[i];
	int mid = (l + r) >> 1;
	if(R <= mid) return res + query(ch[i][0], l, mid, L, R);
	else if(L > mid) return res + query(ch[i][1], mid+1, r, L, R);
	return res + query(ch[i][0], l, mid, L, mid) + query(ch[i][1], mid+1, r, mid+1, R);
}
LL Query(int r, int x) { LL res = 0; while(x) res += query(r, 1, n, dfn[top[x]], dfn[x]), x = fa[top[x]]; return res; }
int main () {
	read(n), read(q), read(A);
	for(int i = 1; i <= n; ++i)
		read(a[i].x), a[i].id = i;
	sort(a + 1, a + n + 1);
	memset(fir, -1, sizeof fir);
	for(int i = 1, x, y, z; i < n; ++i)
		read(x), read(y), read(z), add(x, y, z);
	dfs(1, 0), dfs2(1, 1);
	for(int i = 1; i <= n; ++i)
		sumE[i] += sumE[i-1], sumD[i] = sumD[i-1] + dis[a[i].id];
	for(int i = 1; i <= n; ++i) Modify(rt[i]=rt[i-1], a[i].id);
	LL ans = 0, L, R, x;
	while(q--) {
		read(x), read(L), read(R);
		L = (L + ans) % A, R = (R + ans) % A;
		if(L > R) swap(L, R);
		L = lower_bound(a + 1, a + n + 1, node(L, 0)) - a;
		R = upper_bound(a + 1, a + n + 1, node(R, n)) - a - 1;
		ans = dis[x] * (R-L+1) + (sumD[R] - sumD[L-1]) - (Query(rt[R], x) - Query(rt[L-1], x)) * 2;
		printf("%lld
", ans);
	}
}