一、hash(速度快的恐怖)。
http://codevs.cn/problem/1230/
1 #include<stdio.h> 2 #include<ext/pb_ds/assoc_container.hpp> 3 #include<ext/pb_ds/hash_policy.hpp> 4 __gnu_pbds::gp_hash_table<int, bool> gf; 5 inline int in() 6 { 7 int res=0; 8 char c=getchar(); 9 while(c<'0'||c>'9') c=getchar(); 10 while(c>='0'&&c<='9') res=res*10+c-48,c=getchar(); 11 return res; 12 } 13 int main() 14 { 15 int n = in(), m = in(), x; 16 while(n--){ 17 x = in(); 18 gf[x] = true; 19 } 20 while(m--){ 21 x = in(); 22 puts(gf[x] ? "YES" : "NO"); 23 } 24 return 0; 25 }