Add: Solution.java

Author: CodersAcademy006

solution/1900-1999/1900.The Earliest and Latest Rounds Where Players Compete/Solution.java

@@ -0,0 +1,35 @@
+import java.util.*;
+
+public class Solution {
+    private Map<List<Integer>, int[]> memo = new HashMap<>();
+
+    public int[] earliestAndLatest(int n, int firstPlayer, int secondPlayer) {
+        return dp(firstPlayer, n - secondPlayer + 1, n);
+    }
+
+    private int[] dp(int l, int r, int k) {
+        if (l == r) return new int[]{1, 1};
+        if (l > r) return dp(r, l, k);
+
+        List<Integer> key = Arrays.asList(l, r, k);
+        if (memo.containsKey(key)) return memo.get(key);
+
+        int earliest = Integer.MAX_VALUE;
+        int latest = Integer.MIN_VALUE;
+
+        // Enumerate all possible positions
+        for (int i = 1; i <= l; ++i) {
+            for (int j = l - i + 1; j <= r - i + 1; ++j) {
+                if (!(l + r - k / 2 <= i + j && i + j <= (k + 1) / 2)) continue;
+
+                int[] result = dp(i, j, (k + 1) / 2);
+                earliest = Math.min(earliest, result[0] + 1);
+                latest = Math.max(latest, result[1] + 1);
+            }
+        }
+
+        int[] result = new int[]{earliest, latest};
+        memo.put(key, result);
+        return result;
+    }
+}