🚀 Programming Example
C Program to Check whether the Given String is a Palindrome
Palindrome is a string, which when read in both forward and backward way is same.
💻 Program Code
#include <stdio.h>
#include <string.h>
int main(){
char string[20];
int i, length;
int flag = 0;
printf("Enter a string:");
scanf("%s", string);
length = strlen(string);
for(i=0;i < length ;i++){
if(string[i] != string[length-i-1]){
flag = 1;
break;
}
}
if (flag) {
printf("%s is not a palindrome\n", string);
}
else {
printf("%s is a palindrome\n", string);
}
return 0;
}
🖥 Program Output
<b>Output 1</b>
Enter a string:roor
roor is a palindrome
Press any key to continue . . .
<b>Output 2</b>
Enter a string:rum
rum is not a palindrome
Press any key to continue . . .
📘 Explanation
To check if a string is a palindrome or not, a string needs to be compared with the reverse of itself.
Consider a palindrome string: radar,
---------------------------
index: 0 1 2 3 4
value: r a d a r
---------------------------
To compare it with the reverse of itself, the following logic is used:
- 0th character in the char array, string1 is same as 4th character in the same string.
- 1st character is same as 3rd character.
- 2nd character is same as 2nd character.
- . . . .
- ith character is same as 'length-i-1'th character.
- If any one of the above condition fails, flag is set to true(1), which implies that the string is not a palindrome.
- By default, the value of flag is false(0). Hence, if all the conditions are satisfied, the string is a palindrome.
🎯 How to learn from this example
First understand the algorithm carefully. Then study the program line-by-line and compare it with the output. Finally, review the explanation section to strengthen your logic and programming understanding.
🔥 Practice suggestion
Rewrite the program without looking at the code. Modify values, conditions or logic and run it again. This helps improve confidence and strengthens coding skills much faster.