January 2022 enrollments are closed and the course commences on 8th of January, 2022. For future cohorts

UNIQUE-BINARY-SEARCH-TREES Solution

/*
*  Author: Arpit Bhayani
*  https://arpitbhayani.me
*/
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define ll long long

#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b

using namespace std;

int i = 0;
char ch;
while((ch = getchar()) != '\n') {
str[i++] = ch;
}
str[i] = '\0';
return i;
}

int numTrees(int n) {
int result = 0;
int * count = (int *) calloc(n+1, sizeof(int));

count = 1;
count = 1;

for(int i = 2; i <= n; i++) {
for(int j = 0; j < i; j++) {
count[i] += count[j] * count[i - j - 1];
}
}
result = count[n];
free(count);

return result;
}

int main(int argc, char *argv[]) {
int n;
scanf("%d", &n);
printf("%d\n", numTrees(n));
return 0;
}