Convert String to Integer

Code

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

int custom_atoi(const char *str) {
    // Your logic here
    int i;
    int val = 0;
    int sign = 1;
    for(i=0; str[i] != '\0'; i++)
    {
    if (str[i] == '+') { i++; }
        else if (str[i] == '-') { sign = -1; i++; }

        if(str[i] != '0' && str[i] != '1' && str[i] != '2' && str[i] != '3' && str[i] != '4' && str[i] != '5' && str[i] != '6' && str[i] != '7' && str[i] != '8' && str[i] != '9')
        {
            //printf("value =. %d\n", val);
            break;
        }    
        

        /*if(str[0] == '-')
        {
            sign = -1;
        }
        else {
            sign = 1;
        }*/

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