代码

#include <arpa/inet.h>
#include "router.h"

#define M 400000009
unsigned data[M];
#define data(x) data[(x)%M]

void ins(const RoutingTableEntry *e) {
	data(0xffffffffffLL&*(long long *)e) = e->nexthop;
}

void init(int n, int q, const RoutingTableEntry *tbl) {
	for (int i = 0; i < n; i++) {
		ins(tbl + i);
	}
}

unsigned query(unsigned addr) {
	
	for (int i = 32; i >= 0; i--) {
		if (data(i*1LL<<32|addr)) {
			return data(i*1LL<<32|addr);
		}
		addr &= ~(1u << (32 - i^24));
	}
	
	return 0;
}

评测结果