Medium
Partition String Into Minimum Beautiful Substrings — Python
Full explanation · Time O(n^2) · Space O(n)
# Time: O(n^2)
# Space: O(n)
# dp
class Solution(object):
def minimumBeautifulSubstrings(self, s):
"""
:type s: str
:rtype: int
"""
max_pow_5 = 1
while max_pow_5*5 <= (1<<len(s))-1:
max_pow_5 *= 5
dp = [float("inf")]*(len(s)+1)
dp[0] = 0
for i in xrange(len(s)):
if s[i] == '0':
continue
curr = 0
for j in xrange(i, len(s)):
curr = curr*2+int(s[j])
if max_pow_5%curr == 0:
dp[j+1] = min(dp[j+1], dp[(i-1)+1]+1)
return dp[-1] if dp[-1] != float("inf") else -1
# Time: O(n^2)
# Space: O(n)
# dp
class Solution2(object):
def minimumBeautifulSubstrings(self, s):
"""
:type s: str
:rtype: int
"""
max_pow_5 = 1
while max_pow_5*5 <= (1<<len(s))-1:
max_pow_5 *= 5
dp = [float("inf")]*(len(s)+1)
dp[0] = 0
for i in xrange(len(s)):
curr = 0
for j in reversed(xrange(i+1)):
curr += int(s[j])<<(i-j)
if s[j] == '1' and max_pow_5%curr == 0:
dp[i+1] = min(dp[i+1], dp[(j-1)+1]+1)
return dp[-1] if dp[-1] != float("inf") else -1