awk, 84 bytes

Result

WA

Duration

689ms

Code [DL]

/T/{t=index($0,"T");s=$0}/K/{k=index($0,"K");for(s="";t--;k--)s=s (k<0?"K":" ")}$0=s

stdin

                                       T          
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                        K                         

stdout

                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                                       T          
                          KKKKKKKKKKKKKK

stderr

strace