Convert String to Integer

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

int custom_atoi(const char *str) {
    // Your logic here
    int index = 0;
    int temp = 0;
    while(str[index] != '\0')
    {
        if(str[index] == '-' || str[index] == '+')
        {
            index++;
            continue;
        }
        else if(str[index] >= '0' && str[index] <= '9')
        {
            temp = (temp*10) + str[index] - '0';
        }
        else{
            if(str[0] == '-')
            {
                temp = temp * (-1);
                // return temp * (-1); //This is also passed
                // temp = 0- temp; //this is also passed
            }
            return temp;
        }
        index++;
    }
    return 0;
}

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;
}