Convert a String to Float

Code

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

float custom_atof(const char *str) {
    float ret_val = 0.0;
    uint32_t decimal = 0, point = 0;
    uint8_t sign_flg = 0;
    
    while(*str == ' ' || *str == '\n'){
        str++;
    }               //remove leading whitespaces if any
    
    if(*str == '-'){
        sign_flg = 1;
        str++;
    }
    else if(*str == '+'){
        str++;
    }
    while((*str != '\0') && (*str != '.')){
        decimal *= 10;
        decimal += (*str - '0');

        str++;
    }
    if(*str == '.'){
        ret_val = 1.0;
        str++;
    }     
    while(*str){
        point *=  10;
        point += (*str - '0');
        ret_val /= 10;
        str++;
    }
    // printf("\n%d %d %f\n", decimal, point, ret_val);
    ret_val = decimal + (point * ret_val);
    
    return (sign_flg) ? -ret_val : ret_val;
}

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