URAL_1021

    可以将问题等效成对于x查找10000-x是否在列表中出现过，二分、哈希等都可以。

#include
     
      #include
      
       #define D 33000#define MAXD 66000#define MIN -32768#define MAX 32767int N, h[MAXD];void init(){    int i, k;    memset(h, 0, sizeof(h));    for(i = 0; i < N; i ++)    {        scanf("%d", &k);        h[D + k] = 1;    }}void solve(){    int i, j, k, ok = 0;    scanf("%d", &N);    for(i = 0; i < N; i ++)    {        scanf("%d", &k);        k = 10000 - k;        if(k >= MIN && k <= MAX && h[D + k])            ok = 1;    }    printf("%s\n", ok ? "YES" : "NO");}int main(){    while(scanf("%d", &N) == 1)    {        init();        solve();    }    return 0;}