uniquebinarysearchtrees

关键词：

 这里需要总结规律：

f(0)=f(1)=1;

f(2)=f(0)*f(1) + f(1)*f(0)

f(3)=f(0)*f(2) + f(1)*f(1) + f(2)*f(0)

class Solution {
public:
    int numTrees(int n) {
        if(n == 0)
            return 1;
        if(n == 1)
            return 1;
            
        vector<int> num(n+1,0);
        num[0] = 1;
        num[1] = 1;
        
        for(int i=2; i<n+1; ++i)
        {
            for(int j=0; j<i; ++j)
                num[i] += num[j]*num[i-1-j];
        }
            
        return num[n];
    }
};

96.uniquebinarysearchtrees

Problemstatement:Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1...n?Forexample,Given n =3,thereare totalof5uniqueBST‘s.13321///321132//212 查看详情

96.uniquebinarysearchtrees

Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1...n?Forexample,Given n =3,thereareatotalof5uniqueBST‘s.13321///321132//2123动态规划：G(n):thenumberof 查看详情

96.uniquebinarysearchtrees

Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1...n?Forexample,Given n =3,thereareatotalof5uniqueBST‘s.13321///321132//2123 解题思路：当选定一个节点之后， 查看详情

uniquebinarysearchtrees(代码片段)

Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1... n?Example:Input:3Output:5Explanation:Givenn=3,thereareatotalof5uniqueBST‘s:13321\\///\\321132//\\2123 查看详情

96.uniquebinarysearchtrees

Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1...n?Forexample,Given n =3,thereareatotalof5uniqueBST‘s.13321///321132//2123问题：给n个不同数，统计所有可构造的二叉搜 查看详情

96.uniquebinarysearchtrees

Given n,howmanystructurallyunique BST‘s (binarysearchtrees)thatstorevalues1...n?Forexample,Given n =3,thereareatotalof5uniqueBST‘s.13321///321132//2123题目含义：这道题要求可行的二叉查找树的数量 查看详情

96.uniquebinarysearchtrees

publicclassSolution{publicintnumTrees(intn){int[]dp=newint[n+1];dp[0]=1;dp[1]=1;for(inti=2;i<=n;i++)for(intj=1;j<=i;j++)dp[i]+=dp[j-1]*dp[i-j];returndp[n];}}　　 查看详情

96.uniquebinarysearchtrees

Givenn,howmanystructurallyuniqueBST‘s(binarysearchtrees)thatstorevalues1...n?Forexample,Givenn=3,thereareatotalof5uniqueBST‘s.13321///321132//2123对1-n组成的ＢＳＴ，如果选定ｉ为根，那１－（ｉ－１）都在根的左子树里，（i+1)-n都在根的右子树里 查看详情

uniquebinarysearchtrees

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leetcode86.uniquebinarysearchtrees

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leetcode96.uniquebinarysearchtrees

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