">#include<vector> using namespace std; bool hasSolution(vector<double> a,double result){ if(a.empty()){ return result==24; } for(int i=0;i<a.size();i++){ vector<double> rest=a; rest.erase(i+rest.begin()); if(hasSolution(rest,result+a[i])||hasSolution(rest,result-a[i]) ||hasSolu...