//れっつバケット法 #include<iostream> #include <string> #include <stdio.h> #include <stdlib.h> #include <math.h> using namespace std; //重なったら1 そうでなければ0 int check(int loc1x, int loc1y, int loc2x, int loc2y){ int kyori = abs(pow(loc2x - loc1x, 2) + pow(loc2y - loc1y, 2) ); //cout << "距離測定:" << loc1[0] << "," << loc1[0] << "と" << loc2[0] << "," << loc2[1] << ":" << kyori << endl; if(kyori < 400){ return 1; } return 0; } int main(){ int max; int count = 0; int expand = 1000; //20000 int loc[100000][2]; int in1; int in2; int block[100000]; int myblock; cin >> max; for(int i=0; i<max; i++){ //データ入力部分 cin >> in1; cin >> in2; myblock = (in1 / expand) * 20 + in2 / expand; loc[i][0] = in1; loc[i][1] = in2; block[i] = myblock; //カウント部分 for(int i2=0; i2<i; i2++){ if(block[i] == myblock){ if(check(in1, in2 ,loc[myblock][0], loc[myblock][1]) == 1){ break; } } } if(loc[myblock][0] != -1){ count ++; } } //中身確認 /* for(int i=0; i<max; i++){ cout << loc[i][0] << "," << loc[i][1] << endl; } */ cout << count << endl; }