DSA 100 DAYS OF LEARNING

  DSA

LANGUAGE OPTED - C++

DAY-2 CHAR ARRAY AND STRINGS

1. Reverse a String

#include <iostream>
#include <algorithm> // For std::reverse
#include <cstring>   // For strlen

int main() {
    char str[] = "Hello, World!";
    int n = strlen(str);

    // Using std::reverse
    std::reverse(str, str + n);
    
    std::cout << "Reversed string: " << str << std::endl;
    
    return 0;
}

2. ASCII VALUES

a-z         97-122

A-Z 65 to 90

space     32

#       35

=       61

@       64

Click here to check out all ASCII Values

3.CASE CONVERSION

4. Check Pallindrome : 

#include <iostream>

#include <cstring>

using namespace std;

int main() {

    char ch[1000];

    cout << "Enter a String: ";

    cin.getline(ch, 1000);

    int n = strlen(ch);

    int l = 0, r = n - 1;

    bool isPalindrome = true;

    while (l <= r) {

        if (ch[l] != ch[r]) {

            isPalindrome = false;

            break;

        }

        l++;

        r--;

    }

    if (isPalindrome) {

        cout << "Palindrome" << endl;

    } else {

        cout << "Not Palindrome" << endl;

    }

    return 0;

}

#include <iostream>

#include <cstring>

#include <algorithm>

using namespace std;

int main() {

    char ch[1000];

    cout << "Enter the string: ";

    cin.getline(ch, 1000);

    

    // Store the original string in temp

    char temp[1000];

    strcpy(temp, ch);

    // Get the length of the string

    int n = strlen(ch);

    // Reverse the string

    reverse(ch, ch + n);

    cout << "The reversed string is: " << ch << endl;

    // Check if the original string (temp) is equal to the reversed string (ch)

    if (strcmp(temp, ch) == 0) {

        cout << "It's a palindrome." << endl;

    } else {

        cout << "It's not a palindrome." << endl;

    }

    return 0;

}

#include <iostream>

#include <cstring>

using namespace std;

int main() {

    char ch[1000];

    cout << "Enter the string: ";

    cin.getline(ch, 1000);

    int n = strlen(ch);

    bool isPalindrome = true;

    for (int i = 0; i < n / 2; i++) {

        if (ch[i] != ch[n - i - 1]) {

            isPalindrome = false;

            break;

        }

    }

    if (isPalindrome) {

        cout << "It's a palindrome." << endl;

    } else {

        cout << "It's not a palindrome." << endl;

    }

    return 0;

}

bool checkPalindrome(char ch[], int n) {

  //n -> length of string

  int i=0;

  int j = n-1;

  while( i<= j) {

    if(ch[i] == ch[j]) {

      i++;

      j--;

    }

    else {

      //characters are not matching

      return false;

    }

  }

  //agar yaha pohjoch gye ho

  //iska matlab saare characters match kr gye h

  ///iska matlab palindrome hai

  //iska matlab return true krdo

  return true;

 

}