Convert a String to Float

Code

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

float custom_atof(const char *str) {

    float num = 0;
    char sign;
    int flg = 0;
    float frac =0;



    while(*str !='\0'){

        if(*str == '+' || *str == '-'){

            sign = *str;
            str++;
            continue;

        } 

        if((*str >= '0' && *str <= '9')&& (flg == 0)){
        
            num = num * 10 + (*str - '0');

        } else if(flg == 1){

            frac = frac * 10 + (*str - '0');

        } else {

            flg = 1;

        };

        str++;

    }

if(frac == 1){
    frac = frac * 0.001;
} else {
frac = frac * 0.01;

}

    num = num + frac;

    if(sign == '-'){

        num = 0 - num;
    }

    return num;

}

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