Create 1429-build-array-where-you-can-find-the-maximum-exactly-k-comparisons.js

Author: everthis

1429-build-array-where-you-can-find-the-maximum-exactly-k-comparisons.js

@@ -0,0 +1,35 @@
+/**
+ * @param {number} n
+ * @param {number} m
+ * @param {number} k
+ * @return {number}
+ */
+const numOfArrays = function (n, m, k) {
+	const mod = 1e9 + 7;
+	const dp = [];
+	for (let i = 0; i <= n; i++) {
+		dp[i] = [];
+		for (let j = 0; j <= m; j++) {
+			dp[i][j] = [];
+		}
+	}
+	// i: length; j: max; c: cost
+	function f(i, j, c) {
+		if (dp[i][j][c] !== undefined) return dp[i][j][c];
+		if (c > i || c > j || c === 0) return (dp[i][j][c] = 0);
+		if (i === 1 && c === 1) return (dp[i][j][c] = 1);
+		let res = 0;
+		// ... (j)
+		for (let b = 1; b < j; b++) {
+			res = (res + f(i - 1, b, c - 1)) % mod;
+		}
+		// ... (1 -> j)
+		res = (res + f(i - 1, j, c) * j) % mod;
+		return (dp[i][j][c] = res);
+	}
+	let res = 0;
+	for (let b = 1; b <= m; b++) {
+		res = (res + f(n, b, k)) % mod;
+	}
+	return res;
+};