1. Quick Sort :

Step 1 : TOP := NULL
Step 2 : If N>1, then : TOP := TOP +1, LOWER [1] := 1, UPPER [1] := N
Step 3 : Repeat steps 4 to 7 while TOP != NULL
Step 4 : Set BEG := LOWER [TOP] , END := UPPER [TOP], TOP := TOP-1;
Step 5 : Call QUICK(A, N, BEG, END, LOC)
Step 6 : If BEG < LOC-1 , then :
TOP := TOP +1 , LOWER [TOP] := BEG , UPPER [TOP] = LOC -1;
Step 7 : If LOC + 1 < END , then :
TOP := TOP + 1 , LOWER [TOP] := LOC +1 , UPPER [TOP] := END.
Step 8 : Exit .