1655. Distribute Repeating Integers

You are given an array of n integers, nums, where there are at most 50 unique values in the array. You are also given an array of m customer order quantities, quantity, where quantity[i] is the amount of integers the ith customer ordered. Determine if it is possible to distribute nums such that:

• The ith customer gets exactly quantity[i] integers,
• The integers the ith customer gets are all equal, and
• Every customer is satisfied.

Return true if it is possible to distribute nums according to the above conditions.

class Solution {
    bool helper(map<int,int>& rCounts, vector<int>& q, int p) {
        if(p == q.size()) return true;
        for(auto it = rCounts.lower_bound(q[p]); it != end(rCounts); it++) {
            int count = it->first;
            int left = it->second;
            if(!left) continue;
            rCounts[count - q[p]]++;
            rCounts[count]--;
            if(helper(rCounts,q,p + 1))
                return true;
            rCounts[count]++;
            rCounts[count - q[p]]--;
        }
        
        return false;
    }
public:
    bool canDistribute(vector<int>& nums, vector<int>& quantity) {
        unordered_map<int, int> counter;
        map<int, int> rCounts;
        for(auto n : nums) counter[n]++;
        for(auto [k, v] : counter) rCounts[v]++;
        sort(quantity.begin(), quantity.end(), greater<int>());
    
        return helper(rCounts, quantity, 0);
    }
};