Convert String to Integer

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

int custom_atoi(const char *str) {
    // Your logic here

    if (!str) return 0;

    int result = 0;
    int sign = 1;
    while (*str) {
        if (*str == '+') sign = 1;
        else if (*str == '-') sign = -1;
        else if (!(*str >= '0' && *str <= '9')) return sign * result;
        else result = 10*result + (*str - '0');
        str++;
    }
    return sign * result;
}

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++;
    }

    printf("%d", custom_atoi(str));
    return 0;
}