Convert String to Integer

Code

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

int custom_atoi(const char *str) {
    int num = 0; 
    int sign = 1; 

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

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;
}

Solving Approach