Given an input string, write a function that returns the Run Length Encoded string for the input string. For example, if the input string is ‘wwwwaaadexxxxxx’, then the function should return ‘w4a3d1e1x6’.
Examples:
Input : str = 'wwwwaaadexxxxxx' Output : 'w4a3d1e1x6'
This problem has existing solution please refer Run Length Encoding link. Here we will solve this problem quickly in python using OrderedDict. Approach is very simple, first we create a ordered dictionary which contains characters of input string as key and 0 as their default value, now we run a loop to count frequency of each character and will map it to it’s corresponding key.
Implementation:
Python3
# Python code for run length encodingfrom collections import OrderedDictdef runLengthEncoding(input): # Generate ordered dictionary of all lower # case alphabets, its output will be # dict = {'w':0, 'a':0, 'd':0, 'e':0, 'x':0} dict=OrderedDict.fromkeys(input, 0) # Now iterate through input string to calculate # frequency of each character, its output will be # dict = {'w':4,'a':3,'d':1,'e':1,'x':6} for ch in input: dict[ch] += 1 # now iterate through dictionary to make # output string from (key,value) pairs output = '' for key,value in dict.items(): output = output + key + str(value) return output# Driver functionif __name__ == "__main__": input="wwwwaaadexxxxxx" print (runLengthEncoding(input)) |
w4a3d1e1x6
Another code:
Python3
def encode(message): encoded_message = "" i = 0 while (i <= len(message)-1): count = 1 ch = message[i] j = i while (j < len(message)-1): if (message[j] == message[j+1]): count = count+1 j = j+1 else: break encoded_message=encoded_message+str(count)+ch i = j+1 return encoded_message#Provide different values for message and test your programencoded_message=encode("ABBBBCCCCCCCCAB")print(encoded_message) |
1A4B8C1A1B
This article is contributed by Shashank Mishra (Gullu). If you like Lazyroar and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the Lazyroar main page and help other Geeks.
