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Find the minimum no of operations to convert a string into a palindrome?

+1 vote

For eg: z is changed to y & not y to z ....the value of alphabets are changed from right to left ( the word apple ,the value of 'e' is reduced to 'd' until it becomes a palindrome or when the value becomes 'a'.

posted Aug 28, 2014 by Hindhuja Ashokkumar Nair

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Can you add some example i.e. what is the input and what is the expected output.
what I can get is one operation is from e to a (for the last character) and another is p to l (for the second character) as l to p is not allowed so number of operation is two only. But I am not clear about my understanding.
Eg: if the input is "abcd" ...we have to change  d->c then the presently changed c is changed from c->b & then again fromb->a ....then the 2nd alphabet from right is coconsidered(c) ...c->b the word becones abba (palindrome) of operations is 4
The value of the alphabets can be reduced by 1unit @ a time ( from e to d  ,and then d can be changed to c & so on until the alphabet is 'a' or the word is a palindrome.
Got it, first we need to find the characters which to be changed and take the sum of the diff.

Let me work on the code by tomorrow :)
:-) thank u so much Sir :-)

2 Answers

+1 vote
    char *input="apple";
    int length=strlen(input);
    int i,j;

    int cost = 0;

       if (input[i] != input[length-1-i])
           if (input[i] < input[length-1-i])
             printf("%c to be changed %c\n", input[length-1-i], input[i]);
             cost += input[length-1-i] - input[i];
             printf("%c to be changed %c\n", input[i], input[length-1-i]);
             cost += input[i] - input[length-1-i];         
    printf("Total cost to make it palindrome - %d\n", cost);
answer Aug 29, 2014 by anonymous
0 votes
           char c[ ]="palindrom";
           int i=0,l,sum=0;
                 if(a[i]<a[l]) {
                        printf("Total operation to convert %c to %c is %d \n",a[l],a[i],a[l]-a[i]);
                  else {
                        printf("Total operation to convert %c to %c is %d \n",a[i],a[l],a[i]-a[l]);
         printf("\nTotal No. of operation= %d",sum);
answer Sep 2, 2014 by Shani Verma
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