Convert a String to Float

Code

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

float custom_atof(const char *str) {
    float result = 0.0f;
    float fraction = 0.0f;

    int i =0;
    int sign = 1;
    int frac_divisor = 1;

    if(str[i] == '-') {
        sign = -1;
        i++;
    } else if(str [i]== '+'){
        sign  = 1;
        i++;
    }

    while(str[i] >='0' && str[i] <='9') {
        result = result * 10 + (str[i] - '0');
        i++;
    }
    if(str[i] == '.') {
        i++;
        while(str[i] >='0' && str[i] <='9') {
            fraction = fraction*10 + (str[i] - '0' );
            frac_divisor *= 10;
            i++;
        }
    }
    result = result + fraction/frac_divisor;
    return result * sign ;
}

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