Ultra Hard: enforce letter counts even without absent clues

For example, with a target word of RALLY ([challenge link]), guessing
LEVEL gives [elsewhere, absent, absent, absent, elsewhere].
This commit makes guessing WORLD afterwards a violation, as there must
be at least two Ls in the target word.

This commit also makes it clearer that, when there is an absent clue,
the count of the letter must be exactly (number of non-absent clues with
that letter).

[challenge link]: https://hellowordl.net/?challenge=cmFsbHk

src/clue.ts

@@ -70,19 +70,7 @@ export function violation(
   for (const { letter, clue } of clues) {
     const upper = letter.toUpperCase();
     const nth = ordinal(i + 1);
-    if (clue === Clue.Absent) {
-      if (difficulty === Difficulty.UltraHard) {
-        const max = clues.filter(
-          (c) => c.letter === letter && c.clue !== Clue.Absent
-        ).length;
-        const count = guess.split(letter).length - 1;
-        if (count > max) {
-          const amount = max ? `more than ${englishNumbers[max]} ` : "";
-          const s = max > 1 ? "s" : "";
-          return `Guess can't contain ${amount}${upper}${s}`;
-        }
-      }
-    } else if (clue === Clue.Correct) {
+    if (clue === Clue.Correct) {
       if (guess[i] !== letter) {
         return nth + " letter must be " + upper;
       }
@@ -93,6 +81,30 @@ export function violation(
         return nth + " letter can't be " + upper;
       }
     }
+    if (difficulty === Difficulty.UltraHard) {
+      const clueCount = clues.filter(
+        (c) => c.letter === letter && c.clue !== Clue.Absent
+      ).length;
+      const guessCount = guess.split(letter).length - 1;
+      const hasAbsent = clues.some(
+        (c) => c.letter === letter && c.clue === Clue.Absent
+      );
+      const amount = englishNumbers[clueCount];
+      const s = clueCount !== 1 ? "s" : "";
+      if (hasAbsent) {
+        if (guessCount !== clueCount) {
+          if (clueCount === 0) {
+            return `Guess can't contain ${upper}`;
+          } else {
+            return `Guess must contain exactly ${amount} ${upper}${s}`;
+          }
+        }
+      } else {
+        if (guessCount < clueCount) {
+          return `Guess must contain at least ${amount} ${upper}${s}`;
+        }
+      }
+    }
     ++i;
   }
   return undefined;