g0001_0100.s0096_unique_binary_search_trees.Solution Maven / Gradle / Ivy
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Java-based LeetCode algorithm problem solutions, regularly updated
package 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)
// #2022_06_21_Time_0_ms_(100.00%)_Space_40.4_MB_(72.43%)
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;
}
}