Convert String to Integer

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

int custom_atoi(const char *str) {
    // Your logic here
     int i,res=0,sign =1;

    for(i=0;str[i];i++){
       
        if (str[i] == '-') {
        sign = -1;
        i++;
        }
        if((str[i]>=97 && str[i]<=122)||(str[i]>=65 && str[i]<=90))
         
        break;

        if(str[i]>='0' &&str[i]<='9')
        {
            res=res*10+(str[i]-'0');
        }
    }
    return sign*res;
}

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;
}