#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,b) for (int i = (a); i <= (b); ++i)
#define REPD(i,a,b) for (int i = (a); i >= (b); --i)
#define FORI(i,n) REP(i,1,n)
#define FOR(i,n) REP(i,0,int(n)-1)
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define vi vector<int>
#define ll long long
#define SZ(x) int((x).size())
#define DBG(v) cerr << #v << " = " << (v) << endl;
#define FOREACH(i,t) for (typeof(t.begin()) i=t.begin(); i!=t.end(); i++)
#define fi first
#define se second
const int N = 5050;
int n;
int sum2[2*N*N], rep2[2*N*N];
int main() {
scanf("%d", &n);
FORI(b,n) FORI(c,n) sum2[b*b+c*c]++;
FORI(b,n) rep2[b*b*2]++;
int res = 0, res_rep = 0;
FORI(k,n) FORI(a,k-1) res += sum2[k*k-a*a];
FORI(k,n) FORI(a,k-1) res_rep += rep2[k*k-a*a];
//printf("%d %d\n", res, res_rep);
printf("%d\n", (res-3*res_rep)/2 + 2*res_rep);
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 | #include <bits/stdc++.h> using namespace std; #define REP(i,a,b) for (int i = (a); i <= (b); ++i) #define REPD(i,a,b) for (int i = (a); i >= (b); --i) #define FORI(i,n) REP(i,1,n) #define FOR(i,n) REP(i,0,int(n)-1) #define mp make_pair #define pb push_back #define pii pair<int,int> #define vi vector<int> #define ll long long #define SZ(x) int((x).size()) #define DBG(v) cerr << #v << " = " << (v) << endl; #define FOREACH(i,t) for (typeof(t.begin()) i=t.begin(); i!=t.end(); i++) #define fi first #define se second const int N = 5050; int n; int sum2[2*N*N], rep2[2*N*N]; int main() { scanf("%d", &n); FORI(b,n) FORI(c,n) sum2[b*b+c*c]++; FORI(b,n) rep2[b*b*2]++; int res = 0, res_rep = 0; FORI(k,n) FORI(a,k-1) res += sum2[k*k-a*a]; FORI(k,n) FORI(a,k-1) res_rep += rep2[k*k-a*a]; //printf("%d %d\n", res, res_rep); printf("%d\n", (res-3*res_rep)/2 + 2*res_rep); return 0; } |
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