#include <iostream>
#include <unordered_set>
using namespace std;
const int mm = 5000;
int N;
unordered_set<int> A;
unordered_set<int> B;
unordered_set<int> intersect;
int r=0;
int cc[2 * (mm + 1) * (mm + 1)];
int dd[2 * (mm + 1) * (mm + 1)];
int main()
{
scanf("%d", &N);
//r = 0;
//A.clear();
//B.clear();
//intersect.clear();
//for(int i=0; i < 2 * (mm + 1) * (mm + 1); i++)
//{
// cc[i] = 0;
// dd[i] = 0;
//};
for (int a = 1; a < N; a++)
{
for (int b = a; b < N; b++)
{
A.insert(a * a + b * b);
cc[a * a + b * b] += 1;
}
}
for (int k = 1; k < N+1; k++)
{
for (int c = 1; c < k; c++)
{
B.insert(k * k - c * c);
dd[k * k - c * c] += 1;
}
};
for (int element : A) {
if (B.count(element) > 0) {
intersect.insert(element);
}
}
for (auto el : intersect) r += cc[el] * dd[el];
printf("%d",r);
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | #include <iostream> #include <unordered_set> using namespace std; const int mm = 5000; int N; unordered_set<int> A; unordered_set<int> B; unordered_set<int> intersect; int r=0; int cc[2 * (mm + 1) * (mm + 1)]; int dd[2 * (mm + 1) * (mm + 1)]; int main() { scanf("%d", &N); //r = 0; //A.clear(); //B.clear(); //intersect.clear(); //for(int i=0; i < 2 * (mm + 1) * (mm + 1); i++) //{ // cc[i] = 0; // dd[i] = 0; //}; for (int a = 1; a < N; a++) { for (int b = a; b < N; b++) { A.insert(a * a + b * b); cc[a * a + b * b] += 1; } } for (int k = 1; k < N+1; k++) { for (int c = 1; c < k; c++) { B.insert(k * k - c * c); dd[k * k - c * c] += 1; } }; for (int element : A) { if (B.count(element) > 0) { intersect.insert(element); } } for (auto el : intersect) r += cc[el] * dd[el]; printf("%d",r); } |
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