SQRBR - Square Brackets

Problem Link

Reference

#include <iostream>
using namespace std;

long long int dp[40][40];

int main()
{
int d, n, k, pos;
cin >> d;
char arr[40];
while(d)
{
cin >> n >> k;

for(int i = 0; i < 2 * n; i++)
{
arr[i] = '?';
}

arr[2 * n] = '\0';

for(int i = 0; i < k; i++)
{
cin >> pos;
arr[pos - 1] = '[';
}

n = 2 * n;

for(int i = 0; i <= n; i++)
{
for(int j = 0; j <= n; j++)
{
if(i == 0 && j == 0)
{
dp[i][j] = 1;
}
else if((i == 0 && j != 0))
{
dp[i][j] = 0;
}
else
{
if(arr[i - 1] == '?')
{
dp[i][j] = dp[i - 1][j + 1] + dp[i - 1][j - 1];
}
else
{
dp[i][j] = dp[i - 1][j - 1];
}
}
}
}

cout << dp[n][0] << endl;
d--;
}
return 0;
}