GFG.java

import java.util.*;
import java.math.*;

class GFG {
	public static BigInteger binomial(int n, int k){
	    if(n < k){
	        return new BigInteger("0");
	    }
		BigInteger dp[][] = new BigInteger[n+1][n+1];
		for(int i=0;i<=n;i++){
			for(int j=0;j<=n;j++){
				if(j == 0 || i == 0 || i == j){
					dp[i][j] = new BigInteger("1");
				} else if(i<j){
					dp[i][j] = (new BigInteger("0")).subtract(new BigInteger("1"));
				} else{
					dp[i][j] = dp[i-1][j].add(dp[i-1][j-1]);
				}
			}
		}
		return dp[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));
		}
	}
}

why did you write "mod(new BigInteger("1000000007")" in return statement?

@yogeshjoshi Modulus your output to 109+7 is mentioned in the question.