#include <bits/stdc++.h>
#pragma GCC optimize("-Ofast")
//#pragma GCC optimize("trapv")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.2,popcnt,abm,mmx,avx2,tune=native")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-funroll-loops")
#define I inline void
#define S struct
#define vi vector<int>
#define vii vector<pair<int, int>>
#define pii pair<int, int>
#define pll pair<ll, ll>
using namespace std;
using ll = long long;
using ld = long double;
const int N = 2e5 + 7, mod = 1e9 + 7;
const ll inf = 2e18;
// How interesting!
int n, m;
int a[N], ans[N];
vector<pair<pii, pii>> v;
vector<int> p = {0};
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("in.in", "r", stdin);
cin >> n >> m;
for (int i = 0; i < n; ++i)
{
cin >> a[i];
p.push_back(-(i + 1));
}
reverse(a, a + n);
a[n] = 1;
for (int i = 0; i < m; ++i)
{
int x, y, z;
cin >> x >> y >> z;
v.push_back({{x, i}, {y, z}});
}
sort(v.begin(), v.end());
sort(p.begin(), p.end());
int k = 0;
for (int i = 0; i <= v.back().first.first; ++i)
{
for (int j = n; ~j; --j)
{
if (j < n)
{
if (p[j + 1] - p[j] > a[j])
{
p[j] = p[j + 1] - 1;
}
else
break;
}
else
{
p[j]++;
}
}
while (k < m && v[k].first.first == i + 1)
{
ans[v[k].first.second] = upper_bound(p.begin(), p.end(), v[k].second.second) - lower_bound(p.begin(), p.end(), v[k].second.first);
++k;
}
}
for (int i = 0; i < m; ++i)
cout << ans[i] << "\n";
return 0;
}
/*
- bounds sir (segtree = 4N, eulerTour = 2N, ...)
- a variable defined twice?
- will overflow?
- is it a good complexity?
- don't mess up indices (0-indexed vs 1-indexed)
- reset everything between testcases.
*/
