### LeetCode Challenge #2300. Successful Pairs of Spells and Potions

You are given two positive integer arrays `spells` and `potions`, of length `n` and `m` respectively, where `spells[i]` represents the strength of the `ith` spell and `potions[j]` represents the strength of the `jth` potion.

You are also given an integer `success`. A spell and potion pair is considered successful if the product of their strengths is at least `success`.

Return an integer array `pairs` of length `n` where `pairs[i]` is the number of potions that will form a successful pair with the `ith` spell.

Example 1:

```Input: spells = [5,1,3], potions = [1,2,3,4,5], success = 7
Output: [4,0,3]
Explanation:
- 0th spell: 5 * [1,2,3,4,5] = [5,10,15,20,25]. 4 pairs are successful.
- 1st spell: 1 * [1,2,3,4,5] = [1,2,3,4,5]. 0 pairs are successful.
- 2nd spell: 3 * [1,2,3,4,5] = [3,6,9,12,15]. 3 pairs are successful.
Thus, [4,0,3] is returned.
```

Example 2:

```Input: spells = [3,1,2], potions = [8,5,8], success = 16
Output: [2,0,2]
Explanation:
- 0th spell: 3 * [8,5,8] = [24,15,24]. 2 pairs are successful.
- 1st spell: 1 * [8,5,8] = [8,5,8]. 0 pairs are successful.
- 2nd spell: 2 * [8,5,8] = [16,10,16]. 2 pairs are successful.
Thus, [2,0,2] is returned.
```

Constraints:

• `n == spells.length`
• `m == potions.length`
• `1 <= n, m <= 105`
• `1 <= spells[i], potions[i] <= 105`
• `1 <= success <= 1010`
##### Video Solution
###### C++ Solution
```				```
class Solution {
public:
int potionCount(vector<int> &potions, long long spell, long long success)
{
long long start=0;
long long end=potions.size()-1;
long long mid=start+(end-start)/2;
long long ans=-1;

while(start<=end)
{
mid=start+(end-start)/2;
if(spell*potions[mid]>=success)
{
ans=mid;
end=mid-1;
}
else if(spell*potions[mid]<success)start=mid+1;
}

if(ans==-1)return 0;

return potions.size()-ans;

}
vector<int> successfulPairs(vector<int>& spells, vector<int>& potions, long long success) {
vector<int> pairs;
sort(potions.begin(),potions.end());

for(auto i:spells)
{
int ans=potionCount(potions,i,success);
pairs.push_back(ans);
}
return pairs;
}
};
```
```