Page 272 - Computer Science Class 11 Without Functions
P. 272
Program 11.2 The number of common characters in a pair of strings
01 '''
02 Objective: To find the number of common characters in a pair of strings
03 Inputs:
04 str1 - string value
05 str2 - string value
06 Output: count of the number of common characters
07 '''
08
09 str1 = input('Enter first string:')
10 str2 = input('Enter second string:')
11
12 str1, str2 = str1.lower(), str2.lower()
13
14 distinctChar = []
15 for char in str1 + str2:
16 if char not in distinctChar:
17 distinctChar.append(char)
18
19 print(f"The number of distinct characters between '{str1}' and '{str2}'
20 is:", len(distinctChar))
11.6.3 Searching for a Substring Within Another String
Let us write a program that searches for a substring in a given string. To achieve this, we take two strings (string and
substr) as inputs.
● Since the two strings may comprise a mix of upper and lowercase characters, we first map them to the same case
(line 13).
● Next, we find the length (lengthSubstr) of the substring (line 14).
● The for loop (lines 15-17) looks for a substring of length lengthSubstr that matches the given substr.
● If substr is found, the program displays True (line 19) and False otherwise (line 21).
Program 11.3 Searching for a substring in another string
01 '''
02 Objective: To search for a substring in given string
03 Input:
04 substr - string value
05 string - string value
06 Output: True - if substr is present in string, False, otherwise
07 '''
08
09 substr = input('Enter the substring:')
10 string = input('Enter the string in which the substring is to searched: ')
11
12 flag = False
13 substr, string = substr.lower(), string.lower()
14 lengthSubstr = len(substr)
15 for index in range(len(string)):
16 if substr == string[index:index+lengthSubstr]:
17 flag = True
18
19 if flag == True:
20 print('Yes, the ', substr, ' is present in the', string)
21 else:
22 print('No, the ', substr, ' is not present in the', string)
270 Touchpad Computer Science-XI

