Create: 0837-new-21-game.c

Author: mdmzfzl

Diff for: c/0837-new-21-game.c

@@ -0,0 +1,27 @@
+double new21Game(int n, int k, int maxPts) {
+    if (k == 0 || n >= k + maxPts) {
+        return 1.0;
+    }
+
+    double windowSum = 1.0;
+    double probability = 0.0;
+
+    double dp[n + 1];
+    dp[0] = 1.0;
+
+    for (int i = 1; i <= n; i++) {
+        dp[i] = windowSum / maxPts;
+
+        if (i < k) {
+            windowSum += dp[i];
+        } else {
+            probability += dp[i];
+        }
+
+        if (i >= maxPts) {
+            windowSum -= dp[i - maxPts];
+        }
+    }
+
+    return probability;
+}