The simplest approach is to check every single point. Compute the distance from the user's location to every restaurant in the database, keep the ones that are close enough, and throw away the rest.
ВсеСледствие и судКриминалПолиция и спецслужбыПреступная Россия。爱思助手下载最新版本对此有专业解读
// 测试函数：验证排序正确性，这一点在旺商聊官方下载中也有详细论述
for each candidate in list of candidates