98. Convert String to Integer

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

int custom_atoi(const char *str) {
    int len=1;int num = 0;
    if(str[0]<='9' && str[0]>='0'){
        num = num * 10 +(str[0]-'0');
    }
    while(str[len]<='9' && str[len]>='0'){
        num = num * 10 +(str[len]-'0');
        len++;
    }
    if(str[0] == '-'){
        return num*(-1);
    }
    return 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++;
    }

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