Problem: Given is a string S. Let T be the concatenation of K copies of S. We can repeatedly perform the following operation: choose a character in T and replace it with a different character. Find the minimum number of operations required to satisfy the following condition: any two adjacent characters in T are different.

Submission attempts (in order):
import sys
import math
import itertools
import collections
import heapq
import re
import numpy as np

rr = lambda: sys.stdin.readline().rstrip()
rs = lambda: map(str, sys.stdin.buffer.readline().split())
ri = lambda: int(sys.stdin.readline())
rm = lambda: map(int, sys.stdin.buffer.readline().split())
rl = lambda: list(map(int, sys.stdin.buffer.readline().split()))

s = rr()
k = ri()
cnt = 0
i = 0
if len(set(s)) == 1:
  print(int(len(s)*k/2))
  exit()
while i < len(s)-1:
  if s[i] == s[i+1]:
    cnt += 1
    i += 1
  i += 1
print(cnt)
cnt1 = 0
i1 = 0
s *= 2
while i1 < len(s)-1:
  if s[i1] == s[i1+1]:
    cnt1 += 1
    i1 += 1
  i1 += 1
print(cnt1)
print((cnt1 - cnt)*(k-1) + cnt)



import sys
import math
import itertools
import collections
import heapq
import re
import numpy as np

rr = lambda: sys.stdin.readline().rstrip()
rs = lambda: map(str, sys.stdin.buffer.readline().split())
ri = lambda: int(sys.stdin.buffer.readline())
rm = lambda: map(int, sys.stdin.buffer.readline().split())
rl = lambda: list(map(int, sys.stdin.buffer.readline().split()))

s = rr()
k = ri()
cnt = 0
for i in range(len(s)-1):
  if len[i] == len[i+1]:
    cnt += 1
print(cnt*k)



import sys
import math
import itertools
import collections
import heapq
import re
import numpy as np

rr = lambda: sys.stdin.readline().rstrip()
rs = lambda: map(str, sys.stdin.buffer.readline().split())
ri = lambda: int(sys.stdin.buffer.readline())
rm = lambda: map(int, sys.stdin.buffer.readline().split())
rl = lambda: list(map(int, sys.stdin.buffer.readline().split()))

s = rr()
k = ri()
cnt = 0
for i in range(len(s)-1):
  if s[i] == s[i+1]:
    cnt += 1
print(cnt*k)



import sys
import math
import itertools
import collections
import heapq
import re
import numpy as np

rr = lambda: str(sys.stdin.buffer.readline().rstrip())
rs = lambda: map(str, sys.stdin.buffer.readline().split())
ri = lambda: int(sys.stdin.buffer.readline())
rm = lambda: map(int, sys.stdin.buffer.readline().split())
rl = lambda: list(map(int, sys.stdin.buffer.readline().split()))

s = rr()
k = ri()
cnt = 0
for i in range(len(s)-1):
  if len[i] == len[i+1]:
    cnt += 1
print(cnt*k)



import sys
import math
import itertools
import collections
import heapq
import re
import numpy as np

rr = lambda: sys.stdin.readline().rstrip()
rs = lambda: map(str, sys.stdin.buffer.readline().split())
ri = lambda: int(sys.stdin.readline())
rm = lambda: map(int, sys.stdin.buffer.readline().split())
rl = lambda: list(map(int, sys.stdin.buffer.readline().split()))

s = rr()
k = ri()
cnt = 0
i = 0
if len(set(s)) == 1:
  print(int(s*k/2))
  exit()
while i < len(s)-1:
  if s[i] == s[i+1]:
    cnt += 1
    i += 1
  i += 1
print(cnt)
cnt1 = 0
i1 = 0
s *= 2
while i1 < len(s)-1:
  if s[i1] == s[i1+1]:
    cnt1 += 1
    i1 += 1
  i1 += 1
print(cnt1)
print((cnt1 - cnt)*(k-1) + cnt)



import sys

s = sys.stdin.readline().rstrip()
k = int(sys.stdin.readline())
cnt = 0
i = 0
l = len(s)
if len(set(s)) == 1:
  print(int(l*k/2))
  exit()
while i < l-1:
  if s[i] == s[i+1]:
    cnt += 1
    i += 2
    continue
  i += 1
cnt1 = 0
i1 = 0
s *= 2
while i1 < l*2-1:
  if s[i1] == s[i1+1]:
    cnt1 += 1
    i1 += 2
    continue
  i1 += 1
print((cnt1 - cnt)*(k-1) + cnt)



Verdicts: Wrong Answer

Runtime Error

Runtime Error

Runtime Error

Runtime Error

Accepted