Not reading characters

Hello everyone. I am making a project for my C class and i cannot find where exactly the flaw is. I have made printf to insert numbers and it works perfectly. After that I have made another printf to insert letters but that's where the problem begins. I insert the cases I told the program to read but it does not accept them. It doesnt even show a message. I am kind of a beginner at C so it could be something just ridiculously easy the solution to the problem.Attachment 16394 This is the program I have made so far. Thank you in advance for any help i do receive.

First off, indent your code.

Code:

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

int inrange(int, int, int, int);
int cubesum(int, int, int, int);
int avsqrsum(int, int, int, int);
int squaresum(int, int, int, int);
int inrage(int, int, int, int);

int main()
{

  int a, b, c, d;
  char chr;

  printf("Eisagete 4 arithmous\n");
  scanf("%d%d%d%d", &a, &b, &c, &d);

  printf("Tora dialekste ena gramma apo ta S, C, A\n");
  scanf("%c", &chr);

  while (chr != 'W') {
    if (inrange(a, b, c, d) == 1) {
      switch (chr) {
      case 'S':
        printf("SUM OF THE SQUARES %d\n", squaresum(a, b, c, d));
        break;
      case 'C':
        printf("SUM OF THE CUBES %d\n", cubesum(a, b, c, d));
        break;
      case 'A':
        printf("AVERAGE OF THE SQUARES %d\n", avsqrsum(a, b, c, d));
        break;
      }                        /*kleinei to switch */
    } /* kleinei to if */
    else
      printf("INVALID DATA\n");
  }                            /* kleinei to while */

  return 0;
}

int inrange(int a, int b, int c, int d)
{
  int flag = 1;
  if ((a >= 10 || a <= 20) || (b >= 10 || b <= 20) || (c >= 10 || c <= 20) || (d >= 10 || d <= 20))
    flag = 1;
  return flag;
}

int squaresum(int a, int b, int c, int d)
{
  return pow(a, 2) + pow(b, 2) + pow(c, 2) + pow(d, 2);
}

int cubesum(int a, int b, int c, int d)
{
  return pow(a, 3) + pow(b, 3) + pow(c, 3) + pow(d, 3);
}

int avsqrsum(int a, int b, int c, int d)
{
  return (pow(a, 2) + pow(b, 2) + pow(c, 2) + pow(d, 2)) / 4;
  return 0;
}

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%c is tricky, because it doesn't obey the usual "skip whitespace" rule that all the other conversions follow.
So you'll probably want

Code:

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// note the initial space in this conversion.
scanf(" %c", &chr);

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