线段树 + 判断奇偶

但是把点权直接拿来更新了

WA on #4

#include <bits/stdc++.h>
#define int long long
#define INF 0x3fffffff
#define INFF 1e18
#define endl '\n'
#define lson id << 1
#define rson id << 1 | 1

using namespace std;

const int N = 2e5 + 5;

int a[N], hd[N], cnt;
int dep[N], L[N], R[N], tot, pre[N];
int lz[N << 2];

struct Edge {
	int to, nx;
} e[N];

void add(int u, int v) {
	e[ ++ cnt] = {v, hd[u]}, hd[u] = cnt;
}

void dfs(int u, int fa) {
	dep[u] = dep[fa] + 1, pre[ ++ tot] = u, L[u] = tot;
	for (int i = hd[u]; i; i = e[i].nx) {
		int v = e[i].to;
		if (v == fa) continue;
		dfs(v, u);
	}
	R[u] = tot;
}

void upd(int id, int l, int r, int v) {
	if (l == r) a[pre[l]] += ((dep[pre[l]] & 1) ? v : -v);
	lz[id] += v;
}

void pushdown(int id, int l, int r, int mid) {
	if (lz[id]) {
		upd(lson, l, mid, lz[id]), upd(rson, mid + 1, r, lz[id]);
		lz[id] = 0;
	}
}

void update(int id, int l, int r, int x, int y, int v) {
	if (x <= l && r <= y) {
		if (l == r) a[pre[l]] += ((dep[pre[l]] & 1) ? v : -v);
		lz[id] += v;
		return;
	}
	int mid = (l + r) >> 1;
	pushdown(id, l, r, mid);
	if (x <= mid) update(lson, l, mid, x, y, v);
	if (y > mid) update(rson, mid + 1, r, x, y, v);
}

int query(int id, int l, int r, int x) {
	if (l == r) return a[l];
	int mid = (l + r) >> 1;
	pushdown(id, l, r, mid);
	if (x <= mid) return query(lson, l, mid, x);
	else return query(rson, mid + 1, r, x);
}

signed main() {
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= n; i ++) cin >> a[i];
	for (int i = 1; i < n; i ++) {
		int u, v;
		cin >> u >> v;
		add(u, v), add(v, u);
	}
	dfs(1, 0);
	for (int i = 1; i <= m; i ++) {
		int op, x, y;
		cin >> op;
		if (op == 1) {
			cin >> x >> y;
			update(1, 1, n, L[x], R[x], (dep[x] & 1) ? y : -y);
		} else {
			cin >> x;
			cout << query(1, 1, n, x) << endl;
		}
	}
	return 0;
}

调炸了。

累了。