g0001_0100.s0096_unique_binary_search_trees.Solution Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-java Show documentation

Java-based LeetCode algorithm problem solutions, regularly updated

The newest version!

package g0001_0100.s0096_unique_binary_search_trees;

// #Medium #Dynamic_Programming #Math #Tree #Binary_Tree #Binary_Search_Tree
// #Dynamic_Programming_I_Day_11 #Big_O_Time_O(n)_Space_O(1)
// #2024_11_13_Time_0_ms_(100.00%)_Space_40.7_MB_(6.57%)

public class Solution {
    public int numTrees(int n) {
        long result = 1;
        for (int i = 0; i < n; i++) {
            result *= 2L * n - i;
            result /= i + 1;
        }
        result /= n + 1;
        return (int) result;
    }
}