Convert a String to Float

Code

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

float custom_atof(const char *str) {
    // Your logic here
    //float res = 0.0;
    int i = 0; 
    float num = 0.0 ; 
    float num_decimal = 0.0 ;
    int flag = 0; 
    int decimal_flag = 0; 
    if (str[0] == '-' || str[0] == '+' )
    {

        i = 1; 
    }
    while(str[i] != '\0')
    {
           if (str[i] >= '0' && str[i] <= '9' && flag == 0)
           {
                num  =  (num * 10 ) +  ( int(str[i]) - '0' );
               /// printf("%d" , num);
           }
           
           else if (str[i] >= '0' && str[i] <= '9' && flag == 1 && decimal_flag < 2)
           {
                // 123.45 
                
                num_decimal  =  (num_decimal  * 10 ) +  ( int(str[i]) - '0' ) ;
                decimal_flag ++; 
               
           }
           

           else if (str[i] == '.')
           {
                 flag =  1; 


           }
           else 
           {
            break;
           }
           i ++;
    }
    if (str[0] == '-')
    {
        return 0 - (num +  ((num_decimal)/ 100));
    }
    return num +  ((num_decimal)/ 100);
    
  
;
}

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