nCr [MEDIUM]-Dynamic Programming

Question: 

Find nCr for given n and r.

Input:
First line contains no of test cases T, for every test case 2 integers as inputs (n,r).

Output:
Compute and print the value in seperate line. Modulus your output to 109+7. If n

Constraints:
1<=T<=50
1<=n<=1000
1<=r<=800

Example:
Input:
1
3 2

Output:
3

CODE:

import java.util.*;

import java.lang.*;

import java.io.*;

import java.math.BigInteger;

class GFG {

public static BigInteger binomial(int n, int k){

   if(n < k){

       return new BigInteger("0");

   }

BigInteger comb[][] = new BigInteger[n+1][k+1];

for(int i=0;i<=n;i++){

for(int j=0;j<=Math.min(i,k);j++){

if(j == 0 || i == 0 || i == j){

comb[i][j] = new BigInteger("1");

} else if(i<j){

comb[i][j] = (new BigInteger("0")).subtract(new BigInteger("1"));

} else{

comb[i][j] = comb[i-1][j].add(comb[i-1][j-1]);

}

}

}

return comb[n][k].mod(new BigInteger("1000000007"));

}

public static void main (String[] args) {

Scanner in = new Scanner(System.in);

int t = in.nextInt();

while(t-->0){

   int n = in.nextInt();

   int k = in.nextInt();

   System.out.println(binomial(n,k));

}

}

}

EXECUTION TIME: 1.24s(Ya not good...but better than 3.6+ 😉😉😃😃)