#include <stdio.h>
#include <stdlib.h>

double distance(int x1, int x2, int y1, int y2);

int main() {
    
    int n;
    int basePoint;
    
    printf("Enter the number of points (N)> ");
    scanf("%d", &n);
    printf("Enter the base point (K)> ");
    scanf("%d", &basePoint);
    
    int x[n];
    int y[n];
	double dist[n];
    
    printf("Enter one point per line separated by a space\n");
    int i;
    for(i = 0; i < n; i++)
    {
		printf("Point #%d: ", i+1);
        scanf("%d %d", &x[i], &y[i]);
	}
    
    printf("\nDistances from point #%d\n", basePoint);
    for(i = 0; i < n; i++)
	{
		dist[i]=distance(x[i], x[basePoint-1], y[i], y[basePoint-1]);
        printf("#%d: %g\n", i+1, dist[i]);
    }
	
	double minDist;
	int closest;
	if(basePoint -1 == 0)
	{
		minDist= dist[1];
		closest= 1;
	}
	else
	{
		minDist=dist[0];
		closest=0;
	}
	
	for(i=0; i<n; i++)
	{	
		if(i!= basePoint-1 && dist[i] < minDist)
		{
			minDist=dist[i];
			closest=i;
		}
	}
	
	printf("\nPoint #%d is closest to point #%d\n", closest+1, basePoint);
    system("pause");
	return 0;
}


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