Create 1223-dice-roll-simulation.js

Author: everthis

1223-dice-roll-simulation.js

@@ -0,0 +1,26 @@
+/**
+ * @param {number} n
+ * @param {number[]} rollMax
+ * @return {number}
+ */
+const dieSimulator = function(n, rollMax) {
+  const mod = 10 ** 9 + 7
+  const faces = rollMax.length
+  const dp = Array.from({ length: n + 1 }, () => new Array(faces + 1).fill(0))
+  dp[0][faces] = 1
+  for(let j = 0; j < faces; j++) {
+    dp[1][j] = 1
+  }
+  dp[1][faces] = faces
+  for(let i = 2; i < n + 1; i++) {
+    for(let j = 0; j < faces; j++) {
+      for(let k = 1; k < rollMax[j] + 1; k++) {
+        if(i - k < 0) break
+        dp[i][j] += dp[i - k][faces] - dp[i - k][j]
+        dp[i][j] %= mod
+      }
+    }
+    dp[i][faces] = dp[i].reduce((ac, e) => ac + e, 0)
+  }
+  return dp[n][faces] % mod
+};