#include<cstdio>
#include<iostream>
#include<algorithm>
#include<string>
#include<vector>
#include<cmath>
#include<queue>
#include<queue>
#include<stack>
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef long long LL;
typedef unsigned long long ULL;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<LL> VLL;
typedef vector<LD> VLD;
typedef vector<VLL > VVLL;
typedef vector<VLD > VVLD;
typedef vector<PII > VPII;
typedef vector<PLL > VPLL;
typedef __int128 int128;
template<class TIn>
using indexed_set = tree<
TIn, null_type, less<TIn>,
rb_tree_tag, tree_order_statistics_node_update>;
template<class T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
#define FOR(x, b, e) for(int x=b; x<=(e); ++x)
#define FORD(x, b, e) for(int x=b; x>=(e); --x)
#define REP(x, n) for(int x=0; x<(n); ++x)
#define VAR(v, n) __typeof(n) v = (n)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(x) ((int)(x).size())
#define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define PB push_back
#define ST first
#define ND second
#define THIS (*this)
#define LSB(x) (x & -x)
#define SQR(x) ((x)*(x))
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL); cout.tie(NULL);
int n; cin >> n;
VI a;
VI cnt(n * n + 1);
FOR(i, 1, n) a.PB(i * i);
REP(i, a.size()) REP(j, i) cnt[a[i] - a[j]]++;
LL ans = 0;
REP(i, a.size()) REP(j, i + 1) if (a[i] + a[j] < cnt.size()) ans += cnt[a[i] + a[j]];
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 51 52 53 54 55 56 57 58 59 60 61 62 63 64 | #include<cstdio> #include<iostream> #include<algorithm> #include<string> #include<vector> #include<cmath> #include<queue> #include<queue> #include<stack> #include<bits/stdc++.h> #include<ext/pb_ds/assoc_container.hpp> #include<ext/pb_ds/tree_policy.hpp> using namespace std; using namespace __gnu_pbds; typedef vector<int> VI; typedef vector<VI> VVI; typedef long long LL; typedef unsigned long long ULL; typedef long double LD; typedef pair<int, int> PII; typedef pair<LL, LL> PLL; typedef vector<LL> VLL; typedef vector<LD> VLD; typedef vector<VLL > VVLL; typedef vector<VLD > VVLD; typedef vector<PII > VPII; typedef vector<PLL > VPLL; typedef __int128 int128; template<class TIn> using indexed_set = tree< TIn, null_type, less<TIn>, rb_tree_tag, tree_order_statistics_node_update>; template<class T> using min_heap = priority_queue<T, vector<T>, greater<T>>; #define FOR(x, b, e) for(int x=b; x<=(e); ++x) #define FORD(x, b, e) for(int x=b; x>=(e); --x) #define REP(x, n) for(int x=0; x<(n); ++x) #define VAR(v, n) __typeof(n) v = (n) #define ALL(c) (c).begin(), (c).end() #define SIZE(x) ((int)(x).size()) #define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i) #define PB push_back #define ST first #define ND second #define THIS (*this) #define LSB(x) (x & -x) #define SQR(x) ((x)*(x)) int main() { ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL); int n; cin >> n; VI a; VI cnt(n * n + 1); FOR(i, 1, n) a.PB(i * i); REP(i, a.size()) REP(j, i) cnt[a[i] - a[j]]++; LL ans = 0; REP(i, a.size()) REP(j, i + 1) if (a[i] + a[j] < cnt.size()) ans += cnt[a[i] + a[j]]; cout << ans << '\n'; return 0; } |
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