链接：https://codeforces.com/gym/104168\(\\\)ADivisorDifference签到，输出\(n-1\)即可，复杂度\(O(1)\)。点击查看代码#pragmaGCCoptimize("unroll-loops,Ofast")#include<bits/stdc++.h>usingnamespacestd;usingi64=longlong;#defineendl&