Convert a String to Float

Code

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

float custom_atof(const char *str) {
    int sign = 1; 
    float num = 0; 
    int index = 0; 
    float dec = 0; 
    float div = 10.00;
    int flag = 0; 

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

    while (*str != '\0'){
        if ((*str != '.') && flag == 0){
            num = num * 10 + (*str - '0');
        } else if (flag == 1) {  
            // printf("%d \n", (*str - '0'));
            dec = dec + ((*str - '0') / div);
            div*= 10.00; 
        } else if (*str == '.'){ 
            flag = 1; 
        }
        str++; 
    }

    return (num + dec) * 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