Small problem with century

[Grilofuzeta]

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

void exercise (void);

int century (int y)
{
    int centur = y / 100;
    y &= 100;
    if (y > 0)
        y = centur + 1;
    else
        y = centur;
    return y;
}

void exercise (void)
{
  int y;
  while (scanf ("%d", &y) != EOF)
  {
    int z = century (y);
    printf ("%d\n", z);
  }
}


int main (void)
{
  exercise ();
  return 0;
}

Input:
1900
out:
19 (i need 18)

Input:
1901
Out:
19

i also tested with

if (y > 0)
        y = centur - 1;

and nope... wrong

note:
i cannot change the "void exercise (void)" and main funtion

[Grilofuzeta]

error:

y &= 100;

correct:

y %= 100;

5 and 6 are very close to each other


//lock or delete thread

[vart]

while (scanf ("%d", &y) != EOF)

should be

while (scanf ("%d", &y) == 1)

if user enters something not parsable as decimal integer - for example "abcd" scanf will stop parsing and returns 0
Next call to scanf will encounter same input still present in the input stream and fail again with the same result - so you'll get the infinite loop