Answer to Question #266004 in Python for Gsd

Question

given a sentence , swap the occurrences of the most frequent letter which the least frequent letter and vice-versa. note : .consider upper and lower case letters as different. if there are multiple letters with the same frequency , choose the lowercase letters that comes earliest in dictionary order. if letter like S and B have same frequency consider X. if letter like X and b have same frequency consider b.?

Answer 1

MAX=256 

  

# Function to return the lexicographically 

# smallest after swapping all the 

# occurrences of any two characters 

def smallestStr(str, n): 

  i, j=0,0 

  # To store the first index of 

  # every character of str 

  chk=[0 for i in range(MAX)] 

  for i in range(MAX): 

    chk[i] = -1 

  

  # Store the first occurring 

  # index every character 

  for i in range(n): 

  

    # If current character is appearing 

    # for the first time in str 

    if (chk[ord(str[i])] == -1): 

      chk[ord(str[i])] = i 

  

  # Starting from the leftmost character 

  for i in range(n): 

    flag = False 

  

    # For every character smaller than ord(str[i]) 

    for j in range(ord(str[i])): 

  

      # If there is a character in str which is 

      # smaller than ord(str[i]) and appears after it 

      if (chk[j] > chk[ord(str[i])]): 

        flag = True 

        break 

  

  

    # If the required character pair is found 

    if (flag): 

      break 

  

  # If swapping is possible 

  if (i < n): 

  

    # Characters to be swapped 

    ch1 = (str[i]) 

    ch2 = chr(j) 

  

    # For every character 

    for i in range(n): 

  

      # Replace every ch1 with ch2 

      # and every ch2 with ch1 

      if (str[i] == ch1): 

        str[i] = ch2 

  

      elif (str[i] == ch2): 

        str[i] = ch1 

  

  return "".join(str) 

  

  

# Driver code 

#here you can add you own sentence 

st = "jwdjwjrn" 

str=[i for i in st] 

n = len(str) 

  

print(smallestStr(str, n)) 

#this code considered by expert Umed