#include <bits/stdc++.h> using namespace std; typedef long long int ll; long long count_triples(std::vector<int> h) { ll ans = 0; ll N = h.size(); // i,k,j for(int i=0;i<N;i++){ ll j = i+a[i]; if(j>=N || a[j]>=a[i]) continue; ll k = j-a[j]; ans += (a[k]+a[j]==a[i]); //equidistant if(2*a[j]==a[i]) continue; k = i+a[j]; ans += (a[k]+a[j]==a[i]); } for(int j=0;j<N;j++){ ll i = j-a[j]; if(i<0 || a[i]>=a[j]) continue; ll k = i+a[i]; ans += (a[k]+a[i]==a[j]); //equidistant if(2*a[i]==a[j]) continue; k = j-a[i]; ans += (a[k]+a[j]==a[i]); } return ans; } std::vector<int> construct_range(int M, int K) { vector<int> res; res.push_back(1); for (int i = 1; i < M; i ++) res.push_back(i); return res; } /*void run_part1() { int N; assert(1 == scanf("%d", &N)); std::vector<int> H(N); for (int i = 0; i < N; i++) assert(1 == scanf("%d", &H[i])); fclose(stdin); long long T = count_triples(H); printf("%lld\n", T); fclose(stdout); } void run_part2() { int M, K; assert(2 == scanf("%d %d", &M, &K)); fclose(stdin); std::vector<int> H = construct_range(M, K); int N = H.size(); printf("%d\n", N); for (int i = 0; i < N; i++) printf("%d%c", H[i], " \n"[i + 1 == N]); fclose(stdout); } int main() { int part; assert(1 == scanf("%d", &part)); if (part == 1) run_part1(); else if (part == 2) run_part2(); return 0; }*/

triples.cpp: In function 'long long int count_triples(std::vector<int>)':
triples.cpp:11:18: error: 'a' was not declared in this scope
   11 |         ll j = i+a[i];
      |                  ^
triples.cpp:22:18: error: 'a' was not declared in this scope
   22 |         ll i = j-a[j];
      |                  ^