Create 青蛙上台阶.js

Rain120 · May 30, 2018 · a23a03f · a23a03f
1 parent becf85c
commit a23a03f
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/青蛙上台阶.js b/青蛙上台阶.js
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+/*
+ * 题目描述: 一只青蛙一次最多可以跳上m级台阶。求该青蛙跳上一个n级的台阶总共有多少种跳法。
+ * f(n) = f( n - 1) + f( n -2) + ... + f( n - m)
+ * f(n - 1) = f( n -2) + ... + f( n - 1 - m)
+ **/
+var jumpFloor = function(n, m) { 
+	if (n > m){
+		return 2 * jumpFloor(n - 1, m) - jumpFloor(n - m - 1, m);
+    }
+	if (n === 1) {
+		return 1;
+	} else {
+		return 2 * jumpFloor(n - 1, n);
+	}
+}