http://poj.org/problem?id=1840
1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #define MAXN 25000001 5 using namespace std; 6 short a[MAXN]; 7 int main() 8 { 9 int a1,a2,a3,a4,a5; 10 scanf("%d%d%d%d%d",&a1,&a2,&a3,&a4,&a5); 11 memset(a,0,sizeof(a)); 12 for(int x3=-50; x3<=50; x3++) 13 { 14 if(!x3) continue; 15 for(int x4=-50; x4<=50; x4++) 16 { 17 if(!x4) continue; 18 for(int x5=-50; x5<=50; x5++) 19 { 20 if(!x5) continue; 21 int sum=a3*x3*x3*x3+a4*x4*x4*x4+a5*x5*x5*x5; 22 if(sum<0) sum+=25000000; 23 a[sum]++; 24 } 25 } 26 } 27 int ans=0; 28 for(int x1=-50; x1<=50; x1++) 29 { 30 if(!x1) continue; 31 for(int x2=-50; x2<=50; x2++) 32 { 33 if(!x2) continue; 34 int sum=a1*x1*x1*x1+a2*x2*x2*x2; 35 if(sum<0) sum+=25000000; 36 ans+=a[sum]; 37 } 38 } 39 printf("%d ",ans); 40 return 0; 41 }
map做的：
1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #include<map> 5 #define MAXN 25000001 6 using namespace std; 7 int main() 8 { 9 int a1,a2,a3,a4,a5; 10 scanf("%d%d%d%d%d",&a1,&a2,&a3,&a4,&a5); 11 map<int,int>q; 12 for(int x1=-50; x1<=50; x1++) 13 { 14 if(!x1) continue; 15 for(int x2=-50; x2<=50; x2++) 16 { 17 if(!x2) continue; 18 int sum=a1*x1*x1*x1+a2*x2*x2*x2; 19 if(q.find(sum)==q.end()) 20 q.insert(pair<int,int>(sum,1)); 21 else q[sum]++; 22 } 23 } 24 int ans=0; 25 for(int x3=-50; x3<=50; x3++) 26 { 27 if(!x3) continue; 28 for(int x4=-50; x4<=50; x4++) 29 { 30 if(!x4) continue; 31 for(int x5=-50; x5<=50; x5++) 32 { 33 if(!x5) continue; 34 int sum=a3*x3*x3*x3+a4*x4*x4*x4+a5*x5*x5*x5; 35 if(q.find(sum)==q.end()) continue; 36 ans+=q[0-sum]; 37 } 38 } 39 } 40 printf("%d ",ans); 41 return 0; 42 }