Convert a String to Float

Code

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

float custom_atof(const char *str) {
    // Your logic here
    float res = 0.0f;
    float fraction = 0.1f;
    int sign = 1;
    int is_fraction = 0;

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

    while (*str != '\0')
    {
        if (*str == '.')
        {
            is_fraction = 1;
            str++;
            continue;
        }

        if (*str >= '0' && *str <= '9')
        {
            if (!is_fraction)
            {
                res = res * 10.0f + (*str - '0');
            }else {
                res += (*str - '0') * fraction;
                fraction *= 0.1f;
            }
        }else {
            break;
        }
        str++;
    }
    return res * 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