Geiz-Revive > 洛谷-P3242-接水果

洛谷-P3242-接水果

2019-07-15

莫队

$\Large \color{rgb(0,255,255)}Describe$

树上莫队 + 值域分块，复杂度$\Theta(n\sqrt n+nlogn)$

我们把一个盘子看做是两个点，然后当在莫队同时加入这个两个点时，我们就相应的把这个盘子加入值域分块中，删除同理。用一个$vector$维护每个点上带着的盘子。

值域分块的$trick$和这个题一样，查询$\sqrt n$，加入删除都是$\Theta(1)$的，和莫队的复杂度摊掉了，然后看到$1e9$的值域很显然是要离散化，然后这题差不多就做完了。

本蒟蒻做的时候$LCA$写错调了好久，希望各位不要犯这种睿智错误，$LCA$用的是$\Theta(nlogn)/\Theta(1)$$LCA$

$\Large Code:$

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#pragma region revive
#include <set>
#include <map>
#include <cmath>
#include <queue>
#include <stack>
#include <bitset>
#include <cstdio>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#define inl inline
#define re register int
#define fa(x) t[x].fa
#define son(x, y) t[x].child[y]
#define ls(x) t[x].child[0]
#define rs(x) t[x].child[1]
#define ll long long
const int inf = 0x3f3f3f3f;
#define lowbit(x) ((x) & (-x))
using namespace std;
#ifndef _DEBUG
#define getchar() (*(IOB.in.p++))
#define putchar(c) (*(IOB.out.p++) = (c))
#define io_eof() (IOB.in.p >= IOB.in.pend)
struct IOBUF {
	struct {
		char buff[1 << 26], *p, *pend;
	} in;
	struct {
		char buff[1 << 26], *p;
	} out;
	IOBUF() {
		in.p = in.buff;
		out.p = out.buff;
		in.pend = in.buff + fread(in.buff, 1, 1 << 26, stdin);
	}
	~IOBUF() { fwrite(out.buff, 1, out.p - out.buff, stdout); }
} IOB;
#endif
template <typename IO>
inl void write(IO x) {
	if (x == 0) return (void)putchar('0');
	if (x < 0) putchar('-'), x = -x;
	static char buf[30];
	char *p = buf;
	while (x) {
		*(p++) = x % 10 + '0';
		x /= 10;
	}
	while (p > buf)
		putchar(*(--p));
}
inl void writestr(const char *s) {
	while (*s != 0)
		putchar(*(s++));
}
template <typename IO>
inl void writeln(IO x) { write(x), putchar('\n'); }
template <typename IO>
inl void writesp(IO x) { write(x), putchar(' '); }
inl int readstr(char *s) {
	char *begin = s, c = getchar();
	while (c < 33 || c > 127) {
		c = getchar();
	}
	while (c >= 33 && c <= 127) {
		*(s++) = c;
		c = getchar();
	}
	*s = 0;
	return s - begin;
}
template <typename IO>
inl IO read() {
	IO x = 0;
	register bool w = 0;
	register char c = getchar();
	while (c > '9' || c < '0') {
		if (c == '-') w = 1;
		c = getchar();
	}
	while (c >= '0' && c <= '9') {
		x = (x << 3) + (x << 1) + (c ^ 48);
		c = getchar();
	}
	return w ? -x : x;
}
#pragma endregion
int f[100001][20], dep[50001], st[50001], ed[50001], o[100001], euler[100001], head[50001], mp[100001], lg[100001], len, tot, num, a[100001], b[100001], t[100001];
vector<int> ve[40001];
struct edge {
	int next, to;
} e[100001];
inl void adde(int x, int y) {
	e[++tot] = edge{ head[x], y }, head[x] = tot;
	e[++tot] = edge{ head[y], x }, head[y] = tot;
}
inl void dfs(int x, int fa) {
	euler[++euler[0]] = x, o[++len] = x, st[x] = euler[0], mp[x] = len, dep[x] = dep[fa] + 1;
	for (re i = head[x]; i; i = e[i].next) {
		if (e[i].to != fa) {
			dfs(e[i].to, x);
			o[++len] = x;
		}
	}
	euler[++euler[0]] = x, ed[x] = euler[0];
}
inl int lca(int l, int r) {
	l = mp[l], r = mp[r];
	re x = min(l, r), y = max(l, r), k = lg[y - x + 1];
	l = x, r = y;
	return dep[f[l][k]] < dep[f[r - (1 << k) + 1][k]] ? f[l][k] : f[r - (1 << k) + 1][k];
}
int s[100001], sum[1001], sz[1001], cnt[100001], buc[100001], ans[100001];
inl void init() {
	dfs(1, 0);
	for (re i = 2; i <= len; i++)lg[i] = lg[i >> 1] + 1;
	for (re i = 1; i <= len; i++)f[i][0] = o[i];
	for (re j = 1; j <= lg[len]; j++) {
		for (re i = 1; i + (1 << j) - 1 <= len; i++) {
			f[i][j] = dep[f[i][j - 1]] < dep[f[i + (1 << (j - 1))][j - 1]] ? f[i][j - 1] : f[i + (1 << (j - 1))][j - 1];
		}
	}
	num = sqrt(euler[0]);
	for (re i = 1; i <= euler[0]; i++)s[i] = (i - 1) / num + 1, sz[s[i]]++;
}
bool vis[100001];
struct quiz {
	int l, r, k, lca, id;
	bool operator<(const quiz &a) {
		return s[l] == s[a.l] ? s[l] & 1 ? r < a.r : r > a.r : s[l] < s[a.l];
	}
} q[100001];
inl void add(int x) {
	for (auto i : ve[x])((++buc[i]) == 2) ? (cnt[a[i]]++, sum[s[a[i]]]++) : 0;
}
inl void del(int x) {
	for (auto i : ve[x])(buc[i] == 2) ? (cnt[a[i]]--, buc[i]--, sum[s[a[i]]]--) : (buc[i]--);
}
inl void oper(int x) {
	(vis[x] ^= 1) ? add(x) : del(x);
}
signed main() {
	re n = read<int>(), p = read<int>(), m = read<int>(), x, y, w, f;
	for (re i = 1; i < n; i++) x = read<int>(), y = read<int>(), adde(x, y);
	init();
	for (re i = 1; i <= p; i++) {
		x = read<int>(), y = read<int>(), w = read<int>();
		ve[x].push_back(i), ve[y].push_back(i), a[i] = b[i] = w;
	}
	sort(b + 1, b + 1 + p);
	re siz = unique(b + 1, b + 1 + p) - b - 1;
	for (re i = 1; i <= p; i++) {
		re k = a[i];
		t[a[i] = lower_bound(b + 1, b + 1 + siz, a[i]) - b] = k;
	}
	for (re i = 1; i <= m; i++) {
		x = read<int>(), y = read<int>(), w = read<int>();
		if (st[x] > st[y]) swap(x, y);
		f = lca(x, y);
		if (x != f) q[i] = quiz{ ed[x], st[y], w, f, i };
		else q[i] = quiz{ st[x], st[y], w, 0, i };
	}
	sort(q + 1, q + 1 + m);
	re l = 1, r = 0, res = 0;
	for (re i = 1; i <= m; i++) {
		while (l < q[i].l)oper(euler[l++]);
		while (l > q[i].l)oper(euler[--l]);
		while (r < q[i].r)oper(euler[++r]);
		while (r > q[i].r)oper(euler[r--]);
		if (q[i].lca) oper(q[i].lca);
		res = 0;
		for (re j = 1; j <= s[siz]; j++) {
			if (res + sum[j] < q[i].k)res += sum[j];
			else {
				for (re l = (j - 1) * num + 1, r = l + sz[j] - 1; l <= r; l++) {
					if ((res += cnt[l]) >= q[i].k) {
						ans[q[i].id] = t[l];
						goto begin;
					}
				}
			}
		}
	begin:
		if (q[i].lca)oper(q[i].lca);
	}
	for (re i = 1; i <= m; i++)writeln(ans[i]);
}