Tic Tac Toe in Love2d, 1k Challenge, Minified from 1347 to 948 bytes

tictactoe-challenge-minified.lua

L=love;G=L.graphics;W=267;H=200;F=math.floor;L.load=function()K={0,0,0,0,0,0,0,0,0}end;B={1,3,7,9,5,2,4,6,8}L.mousepressed=function(x,y,a)if C(K,1)or C(K,2)then L.load()else i=F(y/H)*3+F(x/W)+1;if K[i]<1 then K[i]=1;if C(K,1)then return end;for i=1,9 do if K[i]<1 and C(K,2,i)then K[i]=2;return end end;for i=1,9 do if K[i]<1 and C(K,1,i)then K[i]=2;return end end;for i=1,9 do if K[B[i]]<1 then K[B[i]]=2;return end end else for i=1,9 do if K[i]<1 then return end end;L.load()end end end;R=function(b,c,x,y,d)return b[x]==c and b[y]==c and b[d]==c end;C=function(b,c,e)if e then b={unpack(b)}b[e]=c end;return R(b,c,1,2,3)or R(b,c,4,5,6)or R(b,c,7,8,9)or R(b,c,1,4,7)or R(b,c,2,5,8)or R(b,c,3,6,9)or R(b,c,1,5,9)or R(b,c,3,5,7)end;L.draw=function()for i=1,9 do x=(i-1)%3*W;y=F((i-1)/3)*H;G.line(x+W,0,x+W,y+H)G.line(0,y+H,x+W,y+H)if K[i]==1 then G.line(x,y,x+W,y+H)G.line(x,y+H,x+W,y)elseif K[i]==2 then G.circle('line',x+W/2,y+H/2,H/2)end end end

tictactoe-challenge.lua

-- Rather than waiting around for a 1k challenge, I just did one on my own. Took about an hour.
-- The AI isn't a min-max perfect, it'll only take wins, block wins, or grab open corners.
-- Uses the mouse. Doesn't display who won, but will wait for an extra click before resetting
-- so the win can be verified through manual inspection.

L=love
G=L.graphics
W=267
H=200
F=math.floor

L.load = function()
  K = {0,0,0,0,0,0,0,0,0}
end

B = {1, 3, 7, 9, 5, 2, 4, 6, 8}

L.mousepressed=function(x,y,b)
  if C(K,1) or C(K,2) then
    L.load()
  else
    i = F(y/H)*3 + F(x/W) + 1
    if K[i]<1 then 
      K[i]=1

      if C(K,1) then return end

      for i=1,9 do
        if K[i]<1 and C(K,2,i) then
          K[i]=2
          return
        end
      end

      for i=1,9 do
        if K[i]<1 and C(K,1,i) then
          K[i]=2
          return
        end
      end

      for i=1,9 do
        if K[B[i]]<1 then
          K[B[i]]=2
          return
        end
      end
    else
      for i=1,9 do
        if K[i]<1 then return end
      end
      L.load()
    end
  end
end

R = function(k,l,x,y,z)
  return k[x]==l and k[y]==l and k[z]==l
end

C = function(k,l,q)
  if q then k={unpack(k)};k[q]=l end
  return R(k,l,1,2,3) or
         R(k,l,4,5,6) or
         R(k,l,7,8,9) or
         R(k,l,1,4,7) or
         R(k,l,2,5,8) or
         R(k,l,3,6,9) or
         R(k,l,1,5,9) or
         R(k,l,3,5,7)
end

L.draw = function()
  for i=1,9 do
    x=(i-1)%3*W
    y=F((i-1)/3)*H
    G.line(x+W,0,x+W,y+H)
    G.line(0,y+H,x+W,y+H)
    if K[i] == 1 then
      G.line(x,y,x+W,y+H)
      G.line(x,y+H,x+W,y)
    elseif K[i] == 2 then
      G.circle('line',x+W/2,y+H/2,H/2)
    end
  end
end