#Homework by Mike Murr
#OK to post
#hw25

read(`C25.txt`);

#HookSet(L,cell) Inputs a shape L and a cell [i,j], with 1<=i<=nops(L), 1<=j<=L[i],
# and outputs the set of all cells that are (weakly) to the right in the same row,
# and (weakly) down in the same column.

HookSet:=proc(L, cell) local i, j, S, jj, ii;

if nops(cell) <> 2 then
  print(`cell should be a list of 2 positive integers`);
  return(FAIL);
fi;

i:=cell[1];

if i > nops(L) then
  return({});
fi;

j:=cell[2];

if j > L[i] then
  return({});
fi;

S:={};

for jj from j to L[i] do
  S:=S union {[i,jj]};
od;

for ii from i to nops(L) while j <= L[ii] do
  S:=S union {[ii,j]};
od;

print(S);

end proc;

HookSet([5,5,3,2,1],[2,2]);