313. Super Ugly Number.cpp

313. Super Ugly Number



Write a program to find the nth super ugly number.

Super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k.

Example:

Input: n = 12, primes = [2,7,13,19]
Output: 32 
Explanation: [1,2,4,7,8,13,14,16,19,26,28,32] is the sequence of the first 12 
             super ugly numbers given primes = [2,7,13,19] of size 4.
Note:

1 is a super ugly number for any given primes.
The given numbers in primes are in ascending order.
0 < k ≤ 100, 0 < n ≤ 106, 0 < primes[i] < 1000.
The nth super ugly number is guaranteed to fit in a 32-bit signed integer.



class Solution {
public:
    int nthSuperUglyNumber(int n, vector<int>& primes) {
        vector<int> temp;
        vector<int> index(primes.size(),0);
        temp.push_back(1);
        int minnumber = INT_MAX;

        while(temp.size()!=n)
        {
            for(int i = 0;i<primes.size();i++)
            {
                if(primes[i]*temp[index[i]]<minnumber){
                    minnumber = primes[i]*temp[index[i]];
                }
                
            }
            for(int i = 0;i<primes.size();i++)
            {
                if(minnumber==primes[i]*temp[index[i]]){
                    index[i]++;
                }                                                                                          
            }                        
            temp.push_back(minnumber);
            minnumber = INT_MAX;
        }
        return temp.back();
    }
};