#include <bits/stdc++.h> using namespace std; #define ll long long #define ld long double #define all(a) (a).begin(), (a).end() #define allr(a) (a).rbegin(), (a).rend() #define F first #define S second #define pb push_back typedef pair<int, int> pii; typedef pair<ll, ll> pll; /* #ifndef ONLINE_JUDGE #include <cpp-dump.hpp> #endif */ constexpr ll mod = 1e9+7; ll power(ll a, ll b){ ll res = 1; while(b){ if(b&1) res = res * a % mod; a = a * a % mod; b >>= 1; } return res; } /* ll fact[300001]; ll C(ll n, ll k){ if(k < 0 || k > n) return 0; return fact[n] * power(fact[k], mod-2) % mod * power(fact[n-k], mod-2) % mod; } */ void dzik77() { int n; cin >> n; unordered_map<int,int> mp; for (int i = 1; i <= n; i++){ for (int j = i; j <= n; j++){ if(i*i + j*j > n*n) continue; mp[i*i + j*j]++; } } ll ans = 0; for (int i = 1; i <= n; i++){ for (int j = i-1; j >= 1; j--){ ll t = i*i - j*j; if(mp.find(t) != mp.end()) ans += mp[t]; } } cout << ans << '\n'; } int32_t main() { ios::sync_with_stdio(0); cin.tie(0); /* fact[0] = 1; for (int i = 1; i < 300001; i++){ fact[i] = fact[i-1] * i % mod; } */ int t = 1; //cin >> t; while(t--) dzik77(); 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 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 | #include <bits/stdc++.h> using namespace std; #define ll long long #define ld long double #define all(a) (a).begin(), (a).end() #define allr(a) (a).rbegin(), (a).rend() #define F first #define S second #define pb push_back typedef pair<int, int> pii; typedef pair<ll, ll> pll; /* #ifndef ONLINE_JUDGE #include <cpp-dump.hpp> #endif */ constexpr ll mod = 1e9+7; ll power(ll a, ll b){ ll res = 1; while(b){ if(b&1) res = res * a % mod; a = a * a % mod; b >>= 1; } return res; } /* ll fact[300001]; ll C(ll n, ll k){ if(k < 0 || k > n) return 0; return fact[n] * power(fact[k], mod-2) % mod * power(fact[n-k], mod-2) % mod; } */ void dzik77() { int n; cin >> n; unordered_map<int,int> mp; for (int i = 1; i <= n; i++){ for (int j = i; j <= n; j++){ if(i*i + j*j > n*n) continue; mp[i*i + j*j]++; } } ll ans = 0; for (int i = 1; i <= n; i++){ for (int j = i-1; j >= 1; j--){ ll t = i*i - j*j; if(mp.find(t) != mp.end()) ans += mp[t]; } } cout << ans << '\n'; } int32_t main() { ios::sync_with_stdio(0); cin.tie(0); /* fact[0] = 1; for (int i = 1; i < 300001; i++){ fact[i] = fact[i-1] * i % mod; } */ int t = 1; //cin >> t; while(t--) dzik77(); return 0; } |