Convert String to Integer

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

int custom_atoi(const char *str) {
    // Your logic here
    int flag=1;
    int n=strlen(str);
    int num=0;
    char sign;
    for(int i=0;i<n;i++)
    {
        if(!(str[i]>='0' &&str[i]<='9') &&flag==1 &&(str[i]=='-'||str[i]=='+'))
        sign=str[i];
        else if(str[i]>='0' &&str[i]<='9')
        {
            num=(num*10)+str[i]-'0';
        }
        else
        break;
    }
    return (sign=='-')?(-1*num):num;
    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;
}