C ++数组中两点之间的距离

Question

I am having problems understanding what this function is doing, I know its related to finding the distance between two points but I don't see exactly how that is happening...

double closestPoints(double points[], int n)
{
double closest = 100.0;

for (int p1 = 0; p1 < n; p1++)
{
    for (int p2 = 0; p2 < n; p2++)
    {
        if (p1 != p2 && abs(points[p1] - points[p2]) < closest)
        {
            closest = abs(points[p1] - points[p2]);
        }
    }
}
return closest;
}

Could someone help me understand it?

Answer 1

Ok, so with 2 for-statements you just pick all combinations of points (so combine every point with every other).

if(p1 != p2) means that if p1 points to the same point as p2 does, you ignore them (because you cannot calculate distance between one point.

abs(points[p1] - points[p2]) < closest if distance between 2 chosen points is less than current minimum distance, you set your current minimum distance to this distance.

ps. note that abs(points[p1] - points[p2]) is a formula to calculate distance between to points on a line.

Answer 2

This code is taking an array of doubles and finding which of the points is closest together and recording how close they piston. Instead of double closest = 100 you could do double closest = abs(points[0] - points[1]);