g0001_0100.s0096_unique_binary_search_trees.Solution.cs Maven / Gradle / Ivy

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104 LeetCode algorithm problem solutions

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namespace LeetCodeNet.G0001_0100.S0096_unique_binary_search_trees {

// #Medium #Top_100_Liked_Questions #Dynamic_Programming #Math #Tree #Binary_Tree
// #Binary_Search_Tree #Dynamic_Programming_I_Day_11 #Big_O_Time_O(n)_Space_O(1)
// #2024_01_08_Time_13_ms_(98.48%)_Space_26.2_MB_(88.64%)

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;
    }
}
}