Suppose we have two numbers num and k, we have to find the largest product of k contiguous digits in num. We have to keep in mind that num is guaranteed to have >= k digits.
So, if the input is like num = 52689762 and k = 4, then the output will be 3024, largest product of 4 consecutive digits is (8*9*7*6) = 3024.
To solve this, we will follow these steps −
- largest := 0
- cand := 1
- while (quotient of num/10)^(k-1) > 0, do
- digits := (last digit of nums)^k
- cand := 1
- while digits > 0, do
- cand := cand * (digits mod 10)
- if cand is same as 0, then
- come out from the loop
- digits := quotient of digits / 10
- largest := maximum of largest and cand
- num := quotient of nums / 10
- return largest
Let us see the following implementation to get better understanding −
Example
class Solution: def solve(self, num, k): largest = 0 while num // 10 ** (k - 1) > 0: digits = num % 10 ** k cand = 1 while digits > 0: cand *= digits % 10 if cand == 0: break digits //= 10 largest = max(largest, cand) num //= 10 return largest ob = Solution() num = 52689762 k = 4 print(ob.solve(num,k))
Input
52689762, 4
Output
3024