day 7!

12023/07/07.lua

@@ -0,0 +1,99 @@
+io.input("input")
+
+function handtype(hand, is_part2)
+    cards = {}
+    repeats = {}
+    for c in hand:gmatch("[%d%a]") do
+        repeats[c] = repeats[c] and repeats[c]+1 or 1
+        table.insert(cards, c)
+    end
+    njokers = repeats["J"]
+    lenrep = 0
+    for k,v in pairs(repeats) do
+        lenrep = lenrep + 1
+    end
+    if lenrep==1 then --five of a kind
+        return 7 -- five of a kind
+    end
+    if lenrep==2 then --four of a kind or full house
+        if is_part2 and njokers then return 7 end --five of a kind
+        if repeats[cards[1]]==4 or repeats[cards[2]]==4 then
+            return 6 --four of a kind
+        else
+            return 5 --full house
+        end
+    end
+    if lenrep==3 then --three of a kind or two pair
+        if repeats[cards[1]]==3 or repeats[cards[2]]==3 or repeats[cards[3]]==3 then
+            if is_part2 and njokers then return 6 end -- four of a kind
+            return 4 -- three of a kind
+        else
+            if is_part2 and njokers then 
+                if njokers==1 then return 5 --full house (!)
+                else return 6 --four of a kind 
+                end
+            end
+            return 3 -- two pair
+        end
+    end
+    if lenrep==4 then -- one pair
+        if is_part2 and njokers then return 4 end -- three of a kind
+        return 2 -- one pair
+    end
+    if lenrep==5 then -- high card
+        if is_part2 and njokers then return 2 end -- one pair
+        return 1 -- high card
+    end
+end
+
+cardvalues={A=13, K=12, Q=11, J=10, T=9, ["9"]=8, ["8"]=7, ["7"]=6, ["6"]=5, ["5"]=4, ["4"]=3, ["3"]=2, ["2"]=1}
+cardvalues2={A=13, K=12, Q=11, J=0, T=9, ["9"]=8, ["8"]=7, ["7"]=6, ["6"]=5, ["5"]=4, ["4"]=3, ["3"]=2, ["2"]=1}
+function sorthands(a, b)
+    ta, tb = handtype(a.hand, is_part2), handtype(b.hand, is_part2)
+    if ta < tb then
+        return true
+    elseif ta==tb then
+        for i=1,5 do
+            ca, cb = a.hand:sub(i,i), b.hand:sub(i,i)
+            if is_part2 then
+                va, vb = cardvalues2[ca], cardvalues2[cb]
+            else
+                va, vb = cardvalues[ca], cardvalues[cb]
+            end
+            if va==vb then goto continue
+            else return va<vb end
+
+            ::continue::
+        end
+        return false
+    else
+        return false
+    end
+end
+
+set = {}
+for line in io.lines() do
+    h, b = line:match("^([%d%a]+) (%d+)$")
+    b = tonumber(b)
+    table.insert(set, {hand=h, bid=b})
+end
+
+
+table.sort(set, sorthands)
+sum1 = 0
+for i,s in ipairs(set) do
+    hand, bid = s.hand, s.bid
+    sum1 = sum1 + i*bid
+--    print(i, bid, hand, handtype(hand))
+end
+print("part 1", sum1)
+
+is_part2 = true
+table.sort(set, sorthands)
+sum2 = 0
+for i,s in ipairs(set) do
+    hand, bid = s.hand, s.bid
+    sum2 = sum2 + i*bid
+--    print(i, bid, hand, handtype(hand, is_part2))
+end
+print("part 2", sum2)

12023/07/test

@@ -0,0 +1,5 @@
+32T3K 765
+T55J5 684
+KK677 28
+KTJJT 220
+QQQJA 483