Convert String to Integer

Code

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

int custom_atoi(const char *str) {
    // Your logic here
    int length = 0;
    int atoi = 0;
    while (str[length] != '\0') {
        if (str[length]>='0' && str[length]<='9') {
            atoi = atoi*10 + (str[length] - '0');
        }
        if (str[length]<'0' && length > 0) break;
        if (str[length]>'9' && length > 0) break;
        length++;
    }
    if (str[0] == '-') return -1*atoi;
    return atoi;
}

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