number of reduction to make palindrome

num_of_reduction.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define MAX_STR_LEN 10000

int num_of_reduction(const char const * s) {
  if ( s == NULL || 0 == strlen(s) || MAX_STR_LEN < strlen(s) )
    return 0;
  int len = strlen(s), cnt = 0, l = 0, r = len - 1;
  while ( l < r ) {
    int l_num = *(s + l);
    int r_num = *(s + r);
    if ( l_num != r_num )  {
      cnt += abs(l_num - r_num);
    }
    ++l;
    --r;
  }
  return cnt;
}


int main()  {
  int num_of_test_case = 0;
  fscanf(stdin, "%d", &num_of_test_case);
  int* test_cases = (int*) malloc(sizeof(int) * num_of_test_case);
  int i = 0;
  for ( i = 0; i < num_of_test_case; ++i )  {
    char s[MAX_STR_LEN + 1];
    memset(s, '\0', MAX_STR_LEN + 1);
    fscanf(stdin, "%s", s);
    printf("%d\n", num_of_reduction(s));
  }
}

num_of_reduction.py

# python2
import sys


def num_of_reduction(s):
  cnt, m, r = 0, len(s) / 2, len(s) - 1
  for l in range(m):
    l_num, r_num = ord(s[l]), ord(s[r])
    bigger, smaller = max(l_num, r_num), min(l_num, r_num)
    if bigger != smaller:
      cnt += bigger - smaller
    r -= 1
  return cnt

if __name__ == '__main__':
  inp = []
  for line in sys.stdin:
    inp.append(line.strip())
  for i in inp[1:]:
    print num_of_reduction(i)

num_of_reduction3.py

# python3
import sys


def num_of_reduction(s):
  cnt, m, r = 0, int(len(s) / 2), len(s) - 1
  for l in range(m):
    l_num, r_num = ord(s[l]), ord(s[r])
    bigger, smaller = max(l_num, r_num), min(l_num, r_num)
    if bigger != smaller:
      cnt += bigger - smaller
    r -= 1
  return cnt

if __name__ == '__main__':
  inp = []
  for line in sys.stdin:
    inp.append(line.strip())
  for i in inp[1:]:
    print(num_of_reduction(i))

numOfReduction.java

import java.util.Scanner;


public class Solution {
  public static int numOfReduction(final String s)  {
    int cnt = 0;
    int l = 0;
    int r = s.length() - 1;
    while ( l < r ) {
      int lNum = s.charAt(l);
      int rNum = s.charAt(r);
      if ( lNum != rNum ) {
        cnt += Math.abs(lNum - rNum);
      }
      ++l;
      --r;
    }
    return cnt;
  }

  public static void main(String[] args)  {
    Scanner sc = new Scanner(System.in);
    int numberOfLines = Integer.parseInt(sc.nextLine());
    long start = 0;
    for (int i = 1; i<= numberOfLines;i++){
      System.out.println(numOfReduction(sc.nextLine()));
    }
  }
}

numOfReduction.scala

// https://www.hackerrank.com/challenges/the-love-letter-mystery
object Solution {
  def numOfReduction(s: String): Int = {
    var cnt: Int = 0
    var l: Int = 0
    var r: Int = s.length - 1
    while ( l < r ) {
      cnt += Math.abs(s(l) - s(r))
      l += 1;
      r -= 1;
    }
    cnt
  }
  def main(args: Array[String]) {
    val inp = io.Source.stdin.getLines.drop(1)
    for (i <- inp) println(numOfReduction(i))
  }
}