#include <iostream>
#include <vector>
using namespace std;
int main() {
int n;
cin >> n;
ios::sync_with_stdio(0);
cin.tie(0);
int maxi = 24999999;
vector<int> tab(maxi + 1, 0);
for (int y = 1; y <= 5000; y++) {
for (int i = y; i <= 5000; i++) {
int s = y * y + i * i;
if (s > maxi) break;
tab[s]++;
}
}
int result = 0;
for (int k = 1; k <= n; k++) {
for (int h = 1; h < k; h++) {
int s = k * k - h * h;
if (s < 2 or s > maxi) continue;
result += tab[s];
}
}
cout << result;
return 0;
}
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 | #include <iostream> #include <vector> using namespace std; int main() { int n; cin >> n; ios::sync_with_stdio(0); cin.tie(0); int maxi = 24999999; vector<int> tab(maxi + 1, 0); for (int y = 1; y <= 5000; y++) { for (int i = y; i <= 5000; i++) { int s = y * y + i * i; if (s > maxi) break; tab[s]++; } } int result = 0; for (int k = 1; k <= n; k++) { for (int h = 1; h < k; h++) { int s = k * k - h * h; if (s < 2 or s > maxi) continue; result += tab[s]; } } cout << result; return 0; } |
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