python leetcode 263. Ugly Number 264. Ugly Number II 313. Super Ugly Number

263. Ugly Number

class Solution:
    def isUgly(self, num):
        \"\"\"
        :type num: int
        :rtype: bool
        \"\"\" 
        if num<=0:
            return False
        while num%2==0:
            num//=2 
        while num%3==0:
            num//=3
        while num%5==0:
            num//=5 
        return True if num==1 else False

264. Ugly Number II

class Solution:
    def nthUglyNumber(self, n):
        \"\"\"
        :type n: int
        :rtype: int
        \"\"\" 
        if n<0:
            return 0 
        dp=[1]*n 
        i1=i2=i3=0
        for i in range(1,n):
            dp[i]=min(2*dp[i1],3*dp[i2],5*dp[i3])
            if dp[i]==2*dp[i1]: i1+=1 
            if dp[i]==3*dp[i2]: i2+=1
            if dp[i]==5*dp[i3]: i3+=1
        return dp[n-1]

313. Super Ugly Number

class Solution( ):
    def nthSuperUglyNumber(self, n, primes):
        \"\"\"
        :type n: int
        :type primes: List[int]
        :rtype: int
        \"\"\"
        if n<=0:
            return 
        dp=[1]*n
        index=[0]*len(primes)
        for i in range(1,n):
            dp[i]=min([dp[index[j]]*primes[j]  for j in range(len(primes))])
            for j in range(len(primes)):
                if dp[index[j]]*primes[j]==dp[i]:
                    index[j]+=1
        return dp[n-1]