I'm currently working on a challange where I need to divide strings by specifing number into chunks reverse them and than glue those reversed chunnks back together.
I came up with way to execute this, however I could't come up with way to automate this task.
def switch (n, txt):
a = (txt [0:n] [::-1]) #here I devide and reverse the txt
b = (txt [n:2*n] [::-1])
c = (txt [2*n : 3*n] [::-1])
d = (txt [3*n : 4*n] [::-1])
e = (txt [4*n : 5*n] [::-1])
f = (txt [5*n : 6*n] [::-1])
g = (txt [6*n : 7*n] [::-1])
h = (txt [7*n : 8*n] [::-1])````
ch = (txt [8*n : 9*n] [::-1])
i = (txt [9*n : 10*n] [::-1])
j = (txt [10*n : 11*n] [::-1])
k = (txt [11*n : 12*n] [::-1])
l = (txt [12*n : 13*n] [::-1])
m = (txt [13*n : 14*n] [::-1])
return (a + b + c + d + e + f + g + h + ch + i + j + k + l + m ) #and here I glue it back together
print (switch (3, "Potatos are veges")) #The result should be "topotaa s ergevse"
You can loop using range(start,end,n) to jump n positions between two consecutive interations. In each iteration, you reverse a part of the string:
def switch(n, txt):
result = []
for i in range(0,len(txt),n):
result.append(txt[i:i+n].lower()[::-1])
return ''.join(result)
You can also write the loop as a one-liner:
def switch(n, txt):
return ''.join(txt[i:i+n].lower()[::-1] for i in range(0,len(txt),n))
Both of these approaches have linear time complexity, because we carefully slice txt[i:i+n] by parts, and the glue it back together only once.