C++ String Exercises: Count the number of unique characters of two strings

Last update on December 20 2024 12:26:00 (UTC/GMT +8 hours)

Write a C++ program that counts the number of unique characters in two given strings.

Sample Data:
("Apple", "red") -> 6
[ Unique characters: A, p, l, e, r, d ]
("Python", "Java") -> 9
[ Unique characters: P, y, t, h, o, n, J, a v ]

Sample Solution-1:

C++ Code:

#include <bits/stdc++.h> // Includes all standard libraries

using namespace std; // Using the standard namespace

int test(std::string text1, std::string text2) {
    std::string result; // Declare an empty string to store unique characters

    // Loop through each character in the concatenation of text1 and text2
    for(char &ch : text1 + text2) {
        // Check if the character is not already present in the result string
        if (count(result.begin(), result.end(), ch) == 0)
            result += ch; // If the character is not in result, add it
    }

    return result.length(); // Return the length of the resulting string (number of unique characters)
} 

int main() {
    // Declare and initialize two strings
    string text1 = "Python";
    string text2 = "Java";

    cout << "Original Strings:\n";
    cout << "String1: " << text1; // Output the first string
    cout << "\nString2: " << text2; // Output the second string

    cout << "\nTotal number of unique characters of the said two strings: ";
    cout << test(text1, text2) << endl; // Call function test with two strings and output the number of unique characters
}

Sample Output:

Original Strings:
String1: Python
String2: Java
Total number of unique characters of the said two strings: 9

Flowchart:

Sample Solution-2:

C++ Code:

#include <bits/stdc++.h> // Includes all standard libraries

using namespace std; // Using the standard namespace

int test(std::string text1, std::string text2) {
    std::set<char> result; // Define a set to store unique characters

    std::string text = text1 + text2; // Concatenate text1 and text2 into a single string

    // Iterate through each character in the concatenated string
    for (char ch : text) {
        result.insert(ch); // Insert each character into the set (sets only store unique elements)
    }

    return result.size(); // Return the size of the set, which represents the count of unique characters
}

int main() {
    // Declare and initialize two strings
    string text1 = "Python";
    string text2 = "Java";

    cout << "Original Strings:\n";
    cout << "String1: " << text1; // Output the first string
    cout << "\nString2: " << text2; // Output the second string

    cout << "\nTotal number of unique characters of the said two strings: ";
    cout << test(text1, text2) << endl; // Call function test with two strings and output the number of unique characters
}

Sample Output:

Original Strings:
String1: Python
String2: Java
Total number of unique characters of the said two strings: 9

Flowchart:

C++ Code Editor:

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Previous C++ Exercise: Remove all special characters from a given string.