Question

1. Define a function named "find" that accepts two input parameters: "s "and "ch". "s" is an object of the type "string" and "ch" is a character value with the default argument of 'A'. The function looks for the character "ch" in the string  "s" and displays all the indices of its occurrences on the screen. For example, if the caller sends the values of "ABCDBGAB" and 'B' to the function for the parameters "s" and "ch", respectively, the function displays the following message on the screen: "Character B is found at the following indices:1, 4, 7". If the character does not exist in the string the message would be: "Character B is found at the following indices: NONE".
2. Write a program that first reads a string from the keyboard and then repeatedly reads a character from the keyboard and calls the "find" function implemented in the previous step to display all the occurrences of the input character in the string read from the keyboard, on the screen. The program terminates when the user enters a non-alphabetic character. It is assumed that no white-space character will be included neither in the input string nor in the sequence of characters entered to search; i.e. the white-space characters are used as separators of the input data only. A sample run of this program is given below:

Enter a string: "ABC8CBEABC+DE$$"

Enter a character to search: B

Character B is found at the following indices: 1, 5, 8

Enter a character to search: E

Character E is found at the following indices: 6, 12

Enter a character to search: w

Character w is found at the following indices: NONE

Enter a character to search: &

Answer 1

Code:

#include <iostream>

#include <vector>

using namespace std;

void find(string s, char ch)

{

printf("Character %c is found at the following indices: ", ch);

// We declare an Vector of type int to store the indices

vector<int> indices;

// We iterate over the string

for (int i = 0; i < s.length(); i++)

{

// If the character at index i in the string is equal to ch

if (s[i] == ch)

{

// Then we add the index i to the indices vector

indices.push_back(i);

}

}

// If no indices were found for the given character, then we print NONE

if (indices.size() == 0)

{

printf("NONE\n");

}

// Else we print the indices found for the given character

else

{

for (int i = 0; i < indices.size(); i++)

{

printf("%d", indices[i]);

if (i != indices.size() - 1)

{

printf(", ");

}

}

printf("\n");

}

}

int main()

{

printf("Enter a string: ");

// Reading the string from the user

string s;

cin >> s;

// This loop is iterated until an non-alphabetic character is entered by the user

while (true)

{

printf("Enter a character to search: ");

// Reading the character entered by the user

char ch;

cin >> ch;

// If it is alphabetic, then we call the find method.

if ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'))

{

find(s, ch);

}

// Else we break the loop

else

{

break;

}

}

return 0;

}

Sample Output: