Help me in solving PYSTRARR1 problem

help
,
1

My issue

explain

Learning course: Strings using Python
Problem Link: CodeChef: Practical coding for everyone

2 
while i < (len(u)-1):
    if u[i] == 't' and u[i+1] == 'h':
        print('Yes')
        break
    i = i + 1
if i == (len(u) - 1):
    print('no')

Explanation:

I am assuming you are familiar with basics of strings and loops.

Basically we are iterating through the string to check if any character in string is ‘t’ AND its immediately followed by ‘h’. We are using a while loop for this: if integer 'i' is less than length of string ‘u’ -1 we check if u[i] is ‘t’ AND u[i+1] is ‘h’ or not. If it is we print “Yes” and break out of loop, else we just increase ‘i’ and check for this new ‘i’.

Note we are looping from 0 to len(u)-2 (not len(u)-1) as we are checking i and i+1 (incase of len(u)-1, it will give segmentation fault, as u[i+1] = u[len(u)] doesn’t exist.)

Anyway, if we don’t find any 'th' the loop will end with value of i = len(u)-1. So if we have i == len(u)-1, we print “No”

Let me know if anything confuses you.