[组合数学|容斥原理]
模板代码(以求2,3,5,7倍数为例)要点:二进制枚举 vector<int> ans; ans.push_back(2); ans.push_back(3); ans.push_back(5); ans.push_back(7); long long sum=0; for(int i=1;i<(1<<ans.size());i++) { in...