gls库，找到一个点和一组点之间的最小距离？

Question

如何在c ++中使用gsl库找到点（X0，Y0）和一组点{P0，...，Pn}之间的最小距离？ 我有一个多边形包含一组点{P0（X0，Y0），...，P（Xn，Yn）}和一个点C（X0，Y0）， 我想计算C和点集之间的最小距离。

谢谢

Answer 1

double min_dist = DBL_MAX; // some large number
Point pointC; // set this to the point you want to compare
vector<Point> pointList; // push_back all your points
for (auto it = pointList.begin(); it != pointList.end(); ++it)
{
    Point tempPoint = *it;
    // Calculate distance between C and current point
    double newDist = sqrt(pow((tempPoint.x - pointC.x),2) + pow((tempPoint.y - pointC.y),2))
    // Update min_dist if necessary
    min_dist = min(min_dist, newDist)
}

使用某些C ++ 11功能，可以写成

double min_dist = *std::min_element(begin(pointList),
                                    end(pointList),
                                    [pointC](const Point& lhs, const Point& rhs){ return std::hypot(lhs.x - pointC.x, lhs.y - pointC.y) < std::hypot(rhs.x - pointC.x, rhs.y - pointC.y); });