分块+bfs： 

#include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
const int N = (int)2e6;
const int w = 500;//块长度
typedef long long ll;
ll xx, yy, l[N], r[N], num, n, x, y, D[N], v[N];//D[N]记录每一块距离源点最大的d
struct node{
	ll m, r, d, p;
}a[N];
bool cmp_d(node a, node b){
	return a.d < b.d;
}
bool cmp_m(node a, node b){
	return a.m < b.m;
}
ll dfs(){
	queue<ll >q;
	q.push(0);
	ll ans = 1;
	while (q.size()){
		ll t = q.front();
		q.pop();
		for (int i = 1; i <= num; i++){//对于每一个块进行更新
			if (D[i]>a[t].r){//两边暴力
				for (ll j = l[i]; j <= r[i]; j++){
					if (!v[j] && a[j].d <= a[t].r&&a[j].m <= a[t].p){
						q.push(j);
						ans++;
						v[j] = 1;
					}
				}
				break;//已经是最右边的块了，直接break
			}
			while (l[i] <= r[i] && a[l[i]].m <= a[t].p){//距离已经在磁力半径之内，判断质量
				if (!v[l[i]]){
					q.push(l[i]);
					ans++;
				}
				l[i]++;
			}
		}
	}
	retu...