代码

#include"router.h"
#include<ext/pb_ds/assoc_container.hpp>
__gnu_pbds::gp_hash_table<unsigned,unsigned>a[32];
void init(int b,int,const RoutingTableEntry*c){for(int d=0;d<b;d++)a[c[d].len][c[d].addr]=c[d].nexthop;}
unsigned query(unsigned b){for(int c=32;c;b&=~(1u<<--c))if(auto d=a[c].find(b);d!=a[c].end())return d->second;}

评测结果