#include <bits/stdc++.h> using namespace std; #define FOR(i, b) for (int i = 0; i < b; ++i) #define sz(s) (int)s.size() #define all(s) s.begin(), s.end() #define mp make_pair #define pb push_back #define f first #define s second const int N = 5000; unordered_map<int, int> cnt; void solve() { long long n; cin >> n; for (int i = 1; i <= N; ++i) { for (int j = i; j <= N; ++j) { ++cnt[i * i + j * j]; } } long long ans = 0; for (int h = 1; h < n; ++h) { for (int prz = 1; prz <= n; ++prz) { ans += cnt[prz * prz - h * h]; } } cout << ans << '\n'; } int main() { ios::sync_with_stdio(0); cin.tie(0); solve(); }
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 | #include <bits/stdc++.h> using namespace std; #define FOR(i, b) for (int i = 0; i < b; ++i) #define sz(s) (int)s.size() #define all(s) s.begin(), s.end() #define mp make_pair #define pb push_back #define f first #define s second const int N = 5000; unordered_map<int, int> cnt; void solve() { long long n; cin >> n; for (int i = 1; i <= N; ++i) { for (int j = i; j <= N; ++j) { ++cnt[i * i + j * j]; } } long long ans = 0; for (int h = 1; h < n; ++h) { for (int prz = 1; prz <= n; ++prz) { ans += cnt[prz * prz - h * h]; } } cout << ans << '\n'; } int main() { ios::sync_with_stdio(0); cin.tie(0); solve(); } |