#include
#include

typedef struct{
double x;
double y;
}aXis;

double distance(double x1, double y1, double x2, double y2){
return (pow((x1 - x2),2) + pow((y1 - y2),2));
}

void logic(){
std::map rocation;

vector <aXis> station;
vector <int> connectedStation;
int n;
scanf("%d", &n);
for(int i=0;i<n;i++){
    aXis temp;
    scanf("%lf %lf", &temp.x, &temp.y);
    station.push_back(temp);
}
if(n==1){
    printf("0.00\n");return;
}
int visitStation[100]={0};
int current = 0, go, iterator=0;
double result=0, min=50000;

connectedStation.push_back(0);
visitStation[0]=1;
while(1){

    for(int i=0;i<n;i++){
        if(visitStation[i] == 0 && current != i){
            double temp =distance(station[current].x, station[current].y, station[i].x, station[i].y) ;
            if(temp<=min){
                min = temp;
                go = i;
            }
        }
    }
    if(current == connectedStation.back()){
        connectedStation.push_back(go);

// printf("%d -> %d\n", current, go);
current = 0;
visitStation[go] = 1;
iterator=0;
if(result < min)
result = min;
min = 50000;
go=0;
if(connectedStation.size() == n)
break;
}
else
current = connectedStation[++iterator];

}

// for(int i=0;i<n;i++){
// printf("%d\n", connectedStation[i]);
// }
// printf(("\n"));

result = sqrt(result);
printf("%.2lf\n",result);

}

int main(int argc, const char * argv[])
{
int n;
scanf("%d", &n);

for(int i=0;i<n;i++)
    logic();
return 0;

}

프림알고리즘을 제나름대로 구현해보았는데
자꾸 오답이 나오네요.
어떤 예외때문에 오답이 뜨는지 모르겠습니다.ㅠㅠ