https://leetcode.cn/problems/ccw6C7/

Author: masx200

README.md

@@ -45,6 +45,8 @@ Step 2. Add the dependency
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/ccw6C7/
+
 https://leetcode.cn/problems/WhsWhI/
 
 https://leetcode.cn/problems/longest-consecutive-sequence/

WhsWhI/index.ts

@@ -1,3 +1,3 @@
-import longestConsecutive from "../longest-consecutive-sequence/index.ts";
-
-export default longestConsecutive;
+import longestConsecutive from "../longest-consecutive-sequence/index.ts";
+
+export default longestConsecutive;

ccw6C7/index.ts

@@ -0,0 +1,23 @@
+export default function paintingPlan(n: number, k: number): number {
+    if (k === n * n) return 1;
+
+    let res = 0;
+    for (let a = 0; a <= n; a++) {
+        for (let b = 0; b <= n; b++) {
+            if (a * n + b * (n - a) === k) {
+                res += combination(a, n) * combination(b, n);
+            }
+        }
+    }
+    return res;
+}
+export function combination(m: number, n: number): number {
+    if (m === 0) return 1;
+    let num1 = 1;
+    let num2 = 1;
+    let num3 = 1;
+    for (let i = n; i > 0; i--) num1 *= i;
+    for (let i = m; i > 0; i--) num2 *= i;
+    for (let i = n - m; i > 0; i--) num3 *= i;
+    return num1 / (num2 * num3);
+}