Python - 将字符串中的重复字符大写

给定一个带有小写字母的输入字符串，任务是编写一个Python程序来识别字符串中重复的字符并将它们大写。

例子：

Input: programming language

Output: pRoGRAMMiNG lANGuAGe

Explanation: r,m,n,a,g are repeated elements

Input: geeks for geeks

Output: GEEKS for GEEKS

Explanation: g,e,k,s are repeated elements

方法：

• 我们必须将字符串字符键，将字符串中每个字符出现的频率作为字典中的值。
• 遍历字符串并使用字典检查每个字符的频率，如果字符的频率大于 1，则使用 upper()函数将字符更改为大写。

执行：

Python3

# function for changing the
# repeated characters to uppercase
def RepeatedUpper(s):
 
    # declaring dictionary
    dic = {}
 
    # Traversing the string
    for i in s:
 
        # If the character is already
        # present in dictionary then increment
        # the frequency of the character
        if i in dic:
            dic[i] = dic[i]+1
 
   # If the character is not present in
   # the dictionary then inserting
   # the character in the dictionary
        else:
            dic[i] = 1
    ans = ''
 
    # traversing the string
    for i in s:
 
        # if the frequency of the character is
        # greater than one
        if dic[i] > 1:
 
            # change into uppercase
            i = i.upper()
 
        # appending each character to the ans
        ans = ans+i
    return ans
 
 
# Driver code
s = 'geeks for geeks'
# fuction call
print(RepeatedUpper(s))

输出：

GEEKS for GEEKS

时间复杂度： O(n)

空间复杂度： O(n)