Convert a String to Float

Code

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

float custom_atof(const char *str) {
    // Your logic here
    int i;
    float num = 0.0f;
    float mult = 0.1f;
    bool isNeg = false;
    bool beforeDec = true;
    if(str[0]=='-'){
        isNeg = true;
        i=1;
    }
    else if(str[0]=='+'){
        i=1;
    }
    else{
        i=0;
    }
    while(str[i]!='\0'){
        if(beforeDec && str[i]>='0' && str[i]<='9'){
            num = num*10+str[i]-'0';
        }
        else if(!beforeDec && str[i]>='0' && str[i]<='9'){
            num += mult*(str[i]-'0');
            mult *= 0.1f;
        }
        else if(str[i]=='.'){
            beforeDec = false;
        }
        i++;
    }

    return isNeg?-1*num:num;
}

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