#include<bits/stdc++.h> using namespace std; int n; double sq(double a,double a1,double b,double b1){ return sqrt(pow(a-a1,2)+pow(b-b1,2)); } struct edge{ double x,y,z; }e[40005]; int main(){ for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ yan[i][j]=sq(e[i].x,e[j].x,e[i].y,e[j].y)<=e[i].z; } } for(int k=1;k<=n;k++){ for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ if(yan[i][j]==0){ yan[i][j]=yan[i][k]&&yan[k][j]; } } } } 重要部分留了