POJ 2503

hash

#include <stdio.h>#include <memory.h>short hash[25000001];int main(){int a1,a2,a3,a4,a5,x1,x2,x3,x4,x5;while(scanf("%d",&a1)!=EOF){memset(hash,0,sizeof(hash));int max=0;scanf("%d %d %d %d",&a2,&a3,&a4,&a5);int sum1;for(x1=-50;x1<=50;x1++){if(!x1) continue;for(x2=-50;x2<=50;x2++){if(!x2) continue;sum1=a1*x1*x1*x1+a2*x2*x2*x2;sum1=-sum1;sum1=sum1+12500000;//关键字keyhash[sum1]++;//直接定址法}}int sum2;for(x3=-50;x3<=50;x3++){if(!x3) continue;for(x4=-50;x4<=50;x4++){if(!x4) continue;for(x5=-50;x5<=50;x5++){if(!x5) continue;sum2=a3*x3*x3*x3+a4*x4*x4*x4+a5*x5*x5*x5;        if(sum2<-12500000||sum2>12500000) continue;sum2=sum2+12500000;if(hash[sum2]) max+=hash[sum2];}}}printf("%d\n",max);}}