int numTrees(int n) {
int ans=0;
if (n==0) return 1;
if (n<3) return n;
for (int i=0;i<n;i++) ans+=numTrees(i)*numTrees(n-1-i);
return ans;
}
int numTrees(int n) {
if(!n) return 1;
if(n == 1) return 1;
if(n == 2) return 2;
int res = 0;
for(int i = 0; i < n; ++i) res += numTrees(i)*numTrees(n - i - 1);
return res;
}
int numTrees(int n) {
if (n <= 1) return 1;
int total = 0;
for (int i = 0; i <= n - 1; i++) {
total += (numTrees(i) * numTrees(n - 1 - i));
}
return total;
}
// recursion
int numTrees(int n) {
if(n<2) return 1;
int res=0;
for(int i=0; i<n; ++i){
res+=numTrees(i)*numTrees(n-1-i);
}
return res;
}
int numTrees(int n) {
if (n <= 1) return 1;
int res = 0;
for (int i = 0; i <= n-1; i++) {
res += numTrees(i) * numTrees(n-1-i);
}
return res;
}
int numTrees(int n) {
if (n == 0) return 1;
int sum = 0;
for (int i = 0; i < n; ++i)
{
sum += numTrees(i) * numTrees(n-1-i);
}
return sum;
}
int numTrees(int n) {
int result=0;
if(n==0) return 1;
if(n==1) return 1;
for(int i=0;i<n;i++)
{
result += numTrees(i)*numTrees(n-1-i);
}
return result;
}
int numTrees(int n) {
if( n == 0 || n == 1 )
return 1;
else{
int res = 0;
for(int i = 0; i < n; i++ ){
res += numTrees(i) * numTrees( n - 1 - i );
}
return res;
}
}
int numTrees(int s, int e)
{
if( s > e)
return 1;
int trees = 0;
for(int i = s ;i<= e;i++)
{
trees += numTrees(s,i-1) * numTrees(i+1,e);
}
return trees;
}
int numTrees(int n) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if (n==0){return 1;}
if (n==1){return 1;}
int sum=0;
for (int i=1;i<=n;i++){
sum += numTrees(i-1)*numTrees(n-i);
}
return sum;
}
int numTrees2(int n) {
if (n<=0) return 0;
if (n == 1 ) return 1;
int sum=0;
for (int i=1; i<=n; i++){
if (i==1||i==n){
sum += numTrees(n-1);
}else{
sum += (numTrees(i-1) * numTrees(n-i));
}
}
return sum;
}
int numTrees(int n) {
int result = 0;
if(n <= 0) return 0;
if(n == 1) return 1;
for(int i = 0; i < n; i++)
{
int l = numTrees(i);
int r = numTrees(n - i - 1);
if(!l) result += r;
else if(!r) result += l;
else if(l && r) result += l*r;
}
return result;
}
int numTrees(int n) { // 0 ms
if (n < 3) { return n; }
if (_map.find(n) != _map.end()) { return _map[n]; }
long long res = 0;
for (int root = 1; root <= n; ++root) { // take turns to be root
long long left = numTrees(root-1);
long long right = numTrees(n-root);
if (left == 0 || right == 0) { res += (left+right); }
else { res += left * right; }
}
_map[n] = res;
return _map[n];
}
int main()
{
int n;
scanf("%d", &n);
printf("%d\n", numTrees(n));
return 0;
}
int numTrees(int n) {
if (n==0) return 1;
if (n==1) return 1;
vector<int> nTree;
nTree.push_back(numTrees(0));
nTree.push_back(numTrees(1));
for(int i=2;i<n+1;i++){
int tmp;
tmp=0;
for(int j=0;j<i;j++){
tmp+=nTree[j]*nTree[i-1-j];
}
nTree.push_back(tmp);
}
return nTree[n];
}
int numTrees(int n) {
if(n==1)
return 1;
else if(n==2)
return 2;
else
return (long)(4*n-2)*numTrees(n-1)/(n+1);
}
int main(int argc, char** argv)
{
int n=2;
if (argc>1){
n = atoi(argv[1]);
}
printf("%d=%d\n", n, numTrees(n));
return 0;
}
int numTrees(int n) {
vector<int> seq;
int cnt = 0;
while(cnt <= n){
numTrees(seq, cnt);
++cnt;
}
return seq.back();
}
int numTrees(int n)
{
int sum = 0;
if (0 >= n) {
return 1;
}
if (1 == n) {
return 1;
}
for(int i=0; i<n; i++) {
int cur = 1;
cur *= numTrees(i);
cur *= numTrees(n-i-1);
sum += cur;
}
return sum;
}
int numTrees(int n) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
int* array = new int[n];
array[0] = 1;
for(int i = 1; i < n; i ++){
array[i] = numTrees(i);
}
int ret = 0;
for(int i = 0; i < n; i++){
ret += array[i] * array[n-i-1];
}
return ret;
}
void main()
{
time_t start, stop;
time(&start);
int result = 0;
//LSearchInt();
//printf("%s\n", LSearchCharArray());
//StackStringTest();
//TestSingleNumber();
//TestReverseInteger();
//TestMaxProfit();
printf("%d\n", numTrees(9));
time(&stop);
printf("%0.2f milliseconds. \n", (double)clock() / CLOCKS_PER_SEC * 1000);
scanf_s("%d", &result);
}
int main(int argc, const char *argv[])
{
printf("%d\n", numTrees(5)) ;
return 0;
}
int main() {
printf("%d\n", numTrees(4));
return 0;
}
int numTrees(int n) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
return numTrees(1,n);
}
int main() {
cout<<numTrees(3)<<endl;
return 0;
}
int main()
{
for(int i=0; i<10; i++) {
printf("numTrees(%d) == %d\n", i, numTrees(i));
}
}
