Competitive/Collaborative Programming Class

Tips

• C related
  • Read an entire line (ignoring whitespace at begining and end of line): cnt = scanf("%[^\n]\n",str);
    • cnt has the following value possibilities:
      • 0 - blank line read
      • EOF - end of file encountered
      • positive number - characters read
    • %[^\n] is a format regular expression that says to get from beginning of line (^) until end of line (\n)
    • The second \n after the close bracket consumes the end of line
    • Note that this is vulenerable to overflow. If the line length is greater than str is declared for, it will continue to keep going (buffer overflow)
    • Note that white space at begining and end of line are lost
  • A better alternative that does not have a buffer overflow is: cnt = scanf("%10000[^\n]\n",str);
    • This assumes that str was declared to be 10000 characters long and will read a max of 10000 caracters
  • gets alternative that does not have stack overflow issues