Convert a String to Float

Code

#include <stdio.h>
#include <stdint.h>

float custom_atof(const char *str) 
{
    int num =0;
    int sign =1;
    int divisor =1;
    bool dot_flag = false;
    float dec = 0.0f;
  while( *str == ' ' || *str =='\n' || *str =='\t')
  {
    str++;
  }

  if(*str == '-')
  {
    sign = -1;
    str++;
  }else if(*str == '+')
  {
    str++;
  }

  while(*str )
  {
    if(*str != '.' && dot_flag == false)
    {
      num = (num * 10)+((*str)-'0');
    }else if(*str == '.')
    {
     dot_flag =true;
    }else{
     dec = dec *10 +(*str - '0');
     divisor*=10;
    }
    str++;
   }

   return (sign * (num + dec/divisor));

}

int main() {
    char str[101];
    fgets(str, sizeof(str), stdin);

    // Remove newline
    uint8_t i = 0;
    while (str[i]) {
        if (str[i] == '\n') {
            str[i] = '\0';
            break;
        }
        i++;
    }

    float value = custom_atof(str);
    printf("%.2f", value);
    return 0;
}

Solving Approach