2016 US Open Bronze Problem 1

For this problem, my code is failing on 4/10 test cases, 5 7 9, and 10.

This is my code

#include <bits/stdc++.h>

using namespace std;

void setIO(string name = ""){
	ios_base::sync_with_stdio(0); cin.tie(0);
	if(name.size()){
		freopen((name+".in").c_str(), "r", stdin);
		freopen((name+".out").c_str(), "w", stdout);
	}
}


int main(){
//	setIO("diamond");
//	making variables
	int n, k, t = 0, tt= 0;
	cin >> n >> k;
	int d[n];	
	vector<int> allowed;
//	getting all diamond sizes and adding to an array
	for(int i = 0; i < n; i++){
		cin >> d[i];
	}
//  if there is only one element output 1
	if(n == 1){
		cout << 1 << "\n";
		return 0;
	}
//	start looping through all the diamond sizes
	for(int i = 0; i < n; i++){
		// adds whichever element i is on which will be used as the base for testing other values
		allowed.push_back(d[i]);
		// starts at values greater than i to test it with all other values
		for(int j = i + 1; j < n; j++){
			int x = 0;
			// starts looping through all the values inside allowed
			for(int o = 1; o <= allowed.size(); o++){
				// if the element is within k of the element o is on add one to x
				if(abs(d[j] - allowed[o - 1]) <= k){
					x += 1;
				}
				// if d[j] was within k of all the elements that allowed had then add it to allowed and break 
				if(o == (allowed.size())){
					if(x == (allowed.size())){
						allowed.push_back(d[j]);
						break;
					}
				}
			}
		}
		// tt will be set to the amount of values that are withink k of eachother starting at i and if it's greater than t, set t to tt
		tt = allowed.size();
		t = max(t, tt);
		allowed.clear();
	}
	// if there were no values within k of eachother just display one diamond
	if(t != 0){
		cout << t << "\n";
	}else{
		cout << 1 << "\n";
	}
	return 0;
}

I have already tried everything in the debugging module (https://usaco.guide/general/debugging-general?lang=cpp)

add “sort(d, d + n);” to sort the diamonds from smallest to largest