代码

#include "router.h"

// class RoutingTableEntry_z
// {
// public:
//     unsigned addr;
//     unsigned char len;
//     unsigned nexthop;
//     void set(RoutingTableEntry fr)
//     {
//         len = fr.len;
//         nexthop = fr.nexthop;
//         addr = 0;
//         for (int i = 0; i < 4; i++)
//         {
//             addr <<= 8;
//             addr |= (fr.addr >> (i*8)) & 255;
//         }
//     }

// }table[827090];

int N;
const RoutingTableEntry *table;
// unsigned Reverse(unsigned addr)
// {
//     unsigned ret = 0;
//     for (int i = 0; i < 4; i++)
//     {
//         ret <<= 8;
//         ret |= (addr >> (i*8)) & 255;
//     }
//     return ret;
// }

void init(int n, int q, const RoutingTableEntry *a) {
    N = n;
    table = a;
}

unsigned query(unsigned addr) {
    int ret = -1;
    for (int l = 0, r = N - 1; l <= r;)
    {
        int mid = (l + r) >> 1;
        if (table[mid].addr == addr)
        {
            ret = mid;
            r = mid - 1;
        }
        else if (table[mid].addr < addr) l = mid + 1;
        else r = mid - 1;
    }
    return ret == -1 ? 0 : table[ret].nexthop;
}

评测结果