#include "triples.h"
//ᴇᴀᴄʜ ᴘᴇʀꜱᴏɴ ᴡɪʟʟ ᴏɴʟʏ ʜᴀᴠᴇ ᴡʜᴀᴛ ᴛʜᴇʏ ᴇɴᴅᴇᴀᴠᴏᴜʀᴇᴅ ᴛᴏᴡᴀʀᴅꜱ [53:39]
//Author: Sazid Hasan
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double dl;
typedef vector<int> vi;
typedef vector<vector<int>> vii;
typedef vector<ll> vl;
typedef vector<bool> vb;
typedef pair<int,int> pii;
typedef pair<ll, ll> pll;
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) (a*(b/gcd(a,b)))
#define spc " "
#ifdef ONLINE_JUDGE
#define debarr(array)
#define deb(x)
#define del
#else
#define debarr(array) for(int w = 0; w < array.size(); w++) cerr << #array << "-" << w << " = " << array[w] << endl;
#define deb(x) cerr << #x << " = " << x << endl;
#define del cerr << '\n';
#endif
const double PI = acos(-1);
const int MOD = 1000000007;
const int inf = (2147483647);
long long count_triples(std::vector<int> H) {
int n = H.size();
ll cnt = 0;
for(int a = 0; a < n; a++){
int i, j, k;
i = a, j = i+H[i], k = j<n ? i+H[j] : -1;
if(k<n && k>=0 && H[k]==k-j) cnt++;
i = a, j = i+H[i], k = j<n ? j+H[j] : -1;
if(k<n && k>=0 && H[k]==k-i) cnt++;
i = a, k = H[i]+i, j = k<n ? k-H[k] : -1;
if(j<n && j>=0 && H[j]==j-i) cnt++;
j = a, i = j-H[j], k = i>=0 ? j+H[i] : -1;
if(k<n && k>=0 && H[k]==k-i) cnt++;
i = a, k = i+H[i], j = k<n ? i+H[k] : -1;
if(j<n && j>=0 && H[j]==k-j) cnt++;
}
for(int i = 0; i < n; i++){
for(int j = i+1; j < n; j++){
int k = j+H[i];
if(k<n && j-i==H[k] && k-i==H[j] && k-j==H[i]) cnt++;
}
}
return cnt;
}
std::vector<int> construct_range(int M, int K) {
return {1, 1, 1};
}
