100. Convert a String to Float

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

float custom_atof(const char *str) {
    // Your logic here
    int i = 0;
    int sign = 1;
    float division = 10.0f;
    int flag = 0;
    float result = 0.0f;
    float test = 0.0f;
    if (*(str + i) == '-') {
        sign = -1.0f;
        i ++;
    }
    else if (*(str + i) == '+') {
        sign = 1.0f;
        i ++;
    }
    while (*(str + i) != '\0') {
        char ch = *(str + i);
        if (ch == '.') {
            flag = 1;
        }
        if (ch >= '0' && ch <= '9') {
            if (flag == 0) {
                result = result * 10 + (ch - '0');
            }
            else {
                test = test + (ch - '0')/division;
                division *= 10.0f;
            }
        }
        i ++;
    }
    return (result + test) * 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;
}