Create 1900-the-earliest-and-latest-rounds-where-players-compete.js

Author: everthis

1900-the-earliest-and-latest-rounds-where-players-compete.js

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+/**
+ * @param {number} n
+ * @param {number} firstPlayer
+ * @param {number} secondPlayer
+ * @return {number[]}
+ */
+const earliestAndLatest = function (n, firstPlayer, secondPlayer) {
+  const { max, min } = Math
+  const hash = {}
+  function dp(l, r, m) {
+    const key = `${l}${r}${m}`
+    if (hash[key] != null) return hash[key]
+    if (l > r) return dp(r, l, m)
+    if (l === r) return [1, 1]
+    let nxt_m = (m + 1) >> 1
+    let ans = [n, 0]
+    for (let i = 1; i < l + 1; i++) {
+      let l_win = i - 1,
+        l_lose = l - i
+      for (
+        let j = max(r - ~~(m / 2) - 1, 0) + l_lose + 1;
+        j < min(r - 1 - l_win, nxt_m - i) + 1;
+        j++
+      ) {
+        let tmp = dp(i, j, nxt_m)
+        ans = [min(ans[0], tmp[0]), max(ans[1], tmp[1])]
+      }
+    }
+    hash[key] = [ans[0] + 1, ans[1] + 1]
+    return hash[key]
+  }
+
+  return dp(firstPlayer, n - secondPlayer + 1, n)
+}