删数可以这么做么 #include<iostream> (5488)#include<set> using namespace std; set<int> s; const int N = 1e4+10; int main() { int n ; cin>>n; while (n--) { int c; cin>>c; if(s.find(c) == s.end()) { s.insert(c); } else { s.erase(c); int x = c<<1; while(s.find(x) != s.end()){ x<<1; } s.insert(x); } } cout<<*s.rbegin()<<endl; }