1. Set or Clear a Specific Bit in a Register

#include <stdio.h>
unsigned char modifyBit(unsigned char reg, int pos, int mode) {//10 3 1
  unsigned mask = (1U<<pos);
  if(mode==1)
  {
  reg = (reg|mask);
  }
  else
  {
    reg = (reg&(~mask));
  }  
    return reg;
} 
int main() {
    unsigned char reg;
    int pos, mode;
    scanf("%hhu %d %d", &reg, &pos, &mode);
    printf("%d", modifyBit(reg, pos, mode));
    return 0;
}