随记，不定期更新

vector<int> v;
//...edit v
for (auto i=v.size();i>=0;i--){

}

int a=-1;
unsigned int b=12;
a<b;

template<class T1,class T2>
bool cmin(T1 &a,const T2 b){return a>b?a=b,1:0;}
template<class T1,class T2,class ...T3>
bool cmin(T1 &a,const T2 b,const T3 ...rest){return cmin(a,b)||cmin(a,rest...);}