title: Convert String to Integer without using atoi
body: <p>How would I convert string to integer without using atoi from arguments given? Here's what I've tried:</p>
  
  <pre><code>int main(int argc, char *argv[]){
      for(int i = 1; i &lt; argc; i++){
          const char *p = argv[i];
          int j = 0;
          while(isdigit(*p)){
              j = j * 10 + *p - '0';
              p++;
              printf("%d\n", j);
          }
      }
  }
  </code></pre>
  
  <p>For some reason, it's splitting apart and re-adding them again.</p>
  
  <pre><code>$ ./a.out 55 6 50 66
  5
  55
  6
  5
  50
  6
  66
  </code></pre>