Problem:
Score : 200 points

Problem Statement

There are N points in a D-dimensional space.

The coordinates of the i-th point are (X_{i1}, X_{i2}, ..., X_{iD}).

The distance between two points with coordinates (y_1, y_2, ..., y_D) and (z_1, z_2, ..., z_D) is \sqrt{(y_1 - z_1)^2 + (y_2 - z_2)^2 + ... + (y_D - z_D)^2}.

How many pairs (i, j) (i < j) are there such that the distance between the i-th point and the j-th point is an integer?

Constraints

All values in input are integers.

2 \leq N \leq 10

1 \leq D \leq 10

-20 \leq X_{ij} \leq 20

No two given points have the same coordinates. That is, if i \neq j, there exists k such that X_{ik} \neq X_{jk}.

Input

Input is given from Standard Input in the following format:

N D
X_{11} X_{12} ... X_{1D}
X_{21} X_{22} ... X_{2D}
\vdots
X_{N1} X_{N2} ... X_{ND}

Output

Print the number of pairs (i, j) (i < j) such that the distance between the i-th point and the j-th point is an integer.

Sample Input 1

3 2
1 2
5 5
-2 8

Sample Output 1

1

The number of pairs with an integer distance is one, as follows:

The distance between the first point and the second point is \sqrt{|1-5|^2 + |2-5|^2} = 5, which is an integer.

The distance between the second point and the third point is \sqrt{|5-(-2)|^2 + |5-8|^2} = \sqrt{58}, which is not an integer.

The distance between the third point and the first point is \sqrt{|-2-1|^2+|8-2|^2} = 3\sqrt{5}, which is not an integer.

Sample Input 2

3 4
-3 7 8 2
-12 1 10 2
-2 8 9 3

Sample Output 2

2

Sample Input 3

5 1
1
2
3
4
5

Sample Output 3

10

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)


#include<bits/stdc++.h>
using namespace std;

using ll = long long;
using ull = unsigned long long;

const double PI = acos(-1);
const int inf = 2e9;
const ll INF = 2e18;
const ll MOD = 1e9+7;

#define sz(s) (s).size()
#define pb push_back
#define fi first
#define se second
#define REP(i,n) for (int i = 0; i<n; i++)
#define ALL(a) begin(a), end(a)

int main (void) {
    int N,D;
    cin >> N >> D;
    vector<vector<int>> X(N,vector<int>(D));
    REP(i,N) REP(j,D) cin >> X[i][j];
    int ans = 0;
    REP(i,N) for (int j=i+1; j<N; j++) {
        int dist = 0;
        REP(k,D) {
            dist += (X[i][k] - X[j][k])*(X[i][k] - X[j][k]);
        }
        REP(k,1000) {
            if (k*k == dist) {
                ans++;
                break;
            }
        }
        //cout << i << " " << j << " " << dist << endl;
    }
    cout << ans << endl;
    return 0;
}