A了1个点 WA了8个点

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

#define int long long

const int N = 3e6 + 5;

inline int read() {
	
	int w = 1, s = 0; char c;
	while(!isdigit(c = getchar())) if(c == '-') w = -1;
	while(isdigit(c)) s = (s << 1) + (s << 3) + (c & 15), c = getchar();
	return s * w;
}

struct Node { int l, r, v, rand, siz, ans; } tr[N];

inline void push_up(int x) {
	
	tr[x].siz = tr[tr[x].l].siz + tr[tr[x].r].siz + 1;
	tr[x].ans = tr[tr[x].l].ans + tr[tr[x].r].ans + tr[x].v;
}

int rt, siz;

inline int insert(int v) {
	
	tr[++ siz].siz = 1;
	tr[siz].v = tr[siz].ans = v;
	tr[siz].rand = rand();
	return siz;
}

inline void split(int now, int v, int &x, int &y) {
	
	if(!now) x = y = 0;
	else {
		if(tr[now].v <= v) x = now, split(tr[now].r, v, tr[now].r, y);
		else y = now, split(tr[now].l, v, x, tr[now].l);
		push_up(now);
	}	
}

inline int merge(int x, int y) {
	
	if(!x || !y) return x | y;
	if(tr[x].rand < tr[y].rand) {
		tr[x].r = merge(tr[x].r, y);
		push_up(x); return x;
	} else {
		tr[y].l = merge(x, tr[y].l);
		push_up(y); return y;
	}
}

#include <ctime>
int arr[N];

signed main() {
	
	srand(time(NULL));
	int n = read(), q = read(), x, y;
	for(int i = 1; i <= n; i ++ ) rt = merge(rt, insert(0));
	while(q -- ) {
		char opt; int a, b;
		cin >> opt;
		a = read(); b = read();
		if(opt == 'U') {
			split(rt, arr[a], rt, x);
			split(rt, arr[a] - 1, rt, y);
			rt = merge(rt, merge(x, insert(b)));
			arr[a] = b;
		} if(opt == 'Z') {
			split(rt, b - 1, rt, x);
			int sum = tr[rt].ans;
			if(sum >= (a - tr[x].siz) * b) printf("TAK\n");
			else printf("NIE\n");
			rt = merge(rt, x);
		}
	}
}

调了好久