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 res;
    float power  = 1.0;
    int fractionpart = 0;
    int realpart = 0;
    int fractionstart = 0;

    while((str[i] == ' ') || (str[i] == '\t'))
    i++;
    if(str[i] == '-')
    {sign =-1; i++;}
    else if(str[i] == '+') {i++;}
    while(str[i] != '\0')
    {
        if(str[i] == '.') //decimal point
        {
            i++;
            fractionstart = 1;
            continue;
        }
        if(fractionstart ==1)
        {
            fractionpart = fractionpart * 10 + (str[i] - '0');
            power *=10.0;
        }
        else
        {
            realpart  = realpart *10 + (str[i] - '0');
        }
        i++;
    }

    return sign *(realpart + (fractionpart / 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;
}