UVA 10277 Boastin' Red Socks

 #include <iostream>
 #include<cstdio>
 #include<cstring>

 using namespace std;

 unsigned int r,sum,p,q;
 unsigned int st[][];

 unsigned gcd(unsigned a,unsigned b)
 {
     return b?gcd(b,a%b):a;
 }
 /*哈希链表*/
 const int HASH=;
 int head[HASH],next1[HASH];
 int hash1(unsigned int &s)
 {
     return s%HASH;
 }
 int insert(int s)
 {
     int h=hash1(st[s][]);
     int u=head[h];
     while(u)//链表尾一直是0，所以s不能为0
         u=next1[u];
     next1[s]=head[h];//原来的链表头成为s的next
     head[h]=s;//s成为head[h]的链表头
     return ;
 }
 int find(unsigned int s)
 {
     int h=hash1(s);
     int u=head[h];
     while(u)
     {
         if(st[u][]==s) return u;
         u=next1[u];
     }
     return ;
 }
 int main()
 {
     //freopen("/home/user/桌面/in","r",stdin);
     while(scanf("%u%u",&p,&q)==&&(p||q))
     {
         memset(head,,sizeof(head));
         unsigned int i=,x,j=;
         if(p==)
         {
             printf("%d %d\n",,);
             continue;
         }
         x=gcd(p,q);
         p/=x;q/=x;
         for(;i<=;i++)
         {
             unsigned int t=i*i-i;
             if(t%p==)
             {
                 st[j][]=t/p;
                 st[j][]=i;
                 insert(j);
                 j++;
             }
             if(t%q==&&(x=find(t/q)))
             {
                 printf("%u %u\n",st[x][],i-st[x][]);
                 break;
             }
         }
         if(i>) puts("impossible");
     }
     return ;
 }