
    Design a function that analyzes user engagement sequences in a social media platform to identify meaningful interaction patterns, where a pattern is considered meaningful if the sum of its engagement levels equals the length of that sequence. Given a string of engagement metrics where each digit represents different levels of user interaction (0-9), determine how many subsequences exhibit this special relationship between their length and total engagement score.
    

    
from collections import defaultdict

def count_Substrings(s):
    """
    Design a function that analyzes user engagement sequences in a social media platform to identify meaningful interaction patterns, where a pattern is considered meaningful if the sum of its engagement levels equals the length of that sequence. Given a string of engagement metrics where each digit represents different levels of user interaction (0-9), determine how many subsequences exhibit this special relationship between their length and total engagement score.
    

    """
from collections import defaultdict

def count_Substrings(s):
    """
    Design a function that analyzes user engagement sequences in a social media platform to identify meaningful interaction patterns, where a pattern is considered meaningful if the sum of its engagement levels equals the length of that sequence. Given a string of engagement metrics where each digit represents different levels of user interaction (0-9), determine how many subsequences exhibit this special relationship between their length and total engagement score.
    

    """
    n = len(s)
    (count, sum) = (0, 0)
    mp = defaultdict(lambda : 0)
    mp[0] += 1
    for i in range(n):
        sum += ord(s[i]) - ord('0')
        count += mp[sum - (i + 1)]
        mp[sum - (i + 1)] += 1
    return count