易错点:
- 和要用long long存储.
- 读入的吸引半径需要乘方(因为通过(x-x0)*(x-x0)-(y-y0)*(y-y0)获取的值本身就是乘方的).
- (分块)右端点需要用min(n,i+w-1)获取.
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#define ll long long
using namespace std;
const int MAXN=3e5;
struct Node{
ll dis,r;
int m,p;
}a[MAXN];
bool cmp_dis(Node a,Node b){
return a.dis<b.dis;
}
bool cmp_m(Node a,Node b){
return a.m<b.m;
}
int q[MAXN],l,r;
int L[MAXN],R[MAXN],cnt=0;
ll D[MAXN];
bool vis[MAXN];
int main(){
ll x0,y0;
int n;
scanf("%lld%lld%d%lld%d",&x0,&y0,&a[0].p,&a[0].r,&n);
a[0].r*=a[0].r;
for(int i=1;i<=n;i++){
int x,y;
scanf("%d%d%d%d%lld",&x,&y,&a[i].m,&a[i].p,&a[i].r);
a[i].dis=(x-x0)*(x-x0)+(y-y0)*(y-y0);
a[i].r*=a[i].r;
}
sort(a+1,a+n+1,cmp_dis);//先按距离排序
int w=sqrt(n);
for(int i=1;i<=n;i+=w){
L[++cnt]=i,R[cnt]=min(n,i+w-1);
D[cnt]=a[R[cnt]].dis;
sort(a+L[cnt],a+R[cnt]+1,cmp_m);//+1
}
l=r=1,q[1]=0;
while(l<=r){
ll rad=a[q[l]].r;
int p=a[q[l]].p;
l++;
for(int i=1;i<=cnt;i++){
if(D[i]>rad){
for(int j=L[i];j<=R[i];j++){
if(!vis[j]&&a[j].dis<=rad&&a[j].m<=p){
vis[j]=1;
q[++r]=j;
}
}
break;
}
while(L[i]<=R[i]&&a[L[i]].m<=p){
if(!vis[L[i]])
q[++r]=L[i];
L[i]++;
}
}
}
printf("%d
",r-1);
return 0;
}