Convert a String to Float

Code

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

float custom_atof(const char *str) {
    // Your logic here
    int mul = 0, i = 0;
    float sum = 0;

    if(str[0] == '+' || str[0] == '-') i=1;

    for( ; str[i]; i++) {
        mul *= 10;
        if(str[i] != '.') {
            sum = sum * 10 +(str[i] - '0');
        } else {
            mul = 1;
        }
    }

    if(str[0] == '-')
        sum = -sum;

    if(mul)
        return float(sum)/mul;
    else 
        return float(sum);
}

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

float custom_atof(const char *str) {
    // Your logic here
    int mul = 0, i = 0;
    float sum = 0;

    if(str[0] == '+' || str[0] == '-') i=1;

    for( ; str[i]; i++) {
        mul *= 10;
        if(str[i] != '.') {
            sum = sum * 10 +(str[i] - '0');
        } else {
            mul = 1;
        }
    }

    if(str[0] == '-')
        sum = -sum;

    if(mul)
        return float(sum)/mul;
    else 
        return float(sum);
}