Convert a String to Float

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

float custom_atof(const char *str) {
    // Your logic here
    if (!str || str[0] == '\0') return 0.0f;
    int sign = 1;
    float num = 0.0f;
    int power = 1;
    //sign handling
    if (*str == '-') {
        sign = -1;
        str++;
    } else if (*str == '+') {
        str++;
    }

    //phase 1: snowball int
    while (*str != '\0' && *str != '.') {
        num = num * 10 + (*str - '0');
        str++;
    }
    //phase 2: snowball float
    if (*str == '.') {
        str++;
        while (*str != '\0') {
            num = num * 10 + (*str - '0');
            power *= 10;
            str++;
        }
    }
    return sign * (num / power);
}

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;
}