Rich Substrings- RICHSTR

Problem Link

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
int t, n, q, l, r;
vector<int> v;
string s;
std::ios::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
cin >> t;

while(t--)
{
cin >> n >> q;
cin >> s;
v.clear();

for(int i = 0; i < n - 2; i++)
{
if(s[i] == s[i + 1] || s[i + 1] == s[i + 2] || s[i] == s[i + 2])
{
v.push_back(i);
}
}

while(q--)
{
cin >> l >> r;
l--;
r--;

if(r - l + 1 < 3)
{
cout << "NO\n";
continue;
}
auto x = upper_bound(v.begin(), v.end(), l - 1);
    if(x == v.end())
    {
    cout << "NO\n";
    }
    else if(*x >= l && *x + 2 <= r)
      cout << "YES" << endl;
      else
      cout << "NO\n";
}
}
}