Give a string s, count the number of nonempty contiguous substrings that have the same number of 0's and 1's, and all the 0's and all the 1's in these substrings are grouped consecutively. Substrings that occur multiple times are counted the number of times they occur. Example 1: Input: 00110011 Output: 6 Explanation: There are 6 substrings that have equal number of consecutive 1's and 0's: 0011, 01, 1100, 10, 0011, and 01. Notice that some of these substrings repeat and are counted the number of times they occur. Also, 00110011 is not a valid substring because all the 0's and 1's are not grouped together. Example 2: Input: 10101 Output: 4 Explanation: There are 4 substrings: 10, 01, 10, 01 that have equal number of consecutive 1's and 0's. Reference: https:leetcode.comproblemscountbinarysubstringsdescription
def count_binary_substring(s):
    cur = 1
    pre = 0
    count = 0
    for i in range(1, len(s)):
        if s[i] != s[i - 1]:
            count = count + min(pre, cur)
            pre = cur
            cur = 1
        else:
            cur = cur + 1
    count = count + min(pre, cur)
    return count
