// clang-format off #include<bits/stdc++.h> using namespace std; #define ll long long #define ssize(x) int(x.size()) template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';} template<typename T,typename = typename enable_if<!is_same<T,string>::value>::type> auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';} #ifdef DEBUG #define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n' #else #define debug(...) {} #endif // clang-format on int cnt[25000007]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin >> n; set<int> squares; for (int i = 1; i <= n; i++) squares.insert(i * i); for (int i = 1; i <= n; i++) { for (int j = 1; j < i; j++) { cnt[i * i - j * j] += 1; } } int ans = 0; for (int a = 1; a < n; a++) { for (int b = a; a * a + b * b < n * n; b++) { ans += cnt[a * a + b * b]; } } cout << ans << '\n'; 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 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | // clang-format off #include<bits/stdc++.h> using namespace std; #define ll long long #define ssize(x) int(x.size()) template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';} template<typename T,typename = typename enable_if<!is_same<T,string>::value>::type> auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';} #ifdef DEBUG #define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n' #else #define debug(...) {} #endif // clang-format on int cnt[25000007]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin >> n; set<int> squares; for (int i = 1; i <= n; i++) squares.insert(i * i); for (int i = 1; i <= n; i++) { for (int j = 1; j < i; j++) { cnt[i * i - j * j] += 1; } } int ans = 0; for (int a = 1; a < n; a++) { for (int b = a; a * a + b * b < n * n; b++) { ans += cnt[a * a + b * b]; } } cout << ans << '\n'; return 0; } |