Ways to get sum from n dice having m face

Ways to get sum from n dice having m face

  December 19, 2017    

---

idea is to save sum x from possible n dices 
See recursion in reference

import java.util.*;
import java.lang.*;
import java.io.*;
class possibleSumDiceDP
 {
public static long possibleSumDice(int m,int n,int x)
{
long dp[][]=new long[n+1][x+1];//sum x possible from nth dice
//for dice 1
for(int i=0;i<=x && i<=m;++i)
dp[1][i]=1;
for(int i=2;i<=n;++i)
{
for(int j=1;j<=x;++j)
{
for(int k=1;k<=m && k<j;++k)
dp[i][j]+=dp[i-1][j-k]; // possible sum from n-1 dice and k value is taken for nth dice so remaining sum needed is j-k
}
}
return dp[n][x];
}
public static void main (String[] args)
{
Scanner ab=new Scanner(System.in);
int t=ab.nextInt();
while(t-->0)
{
    int m=ab.nextInt();
    int n=ab.nextInt();
    int x=ab.nextInt();
    System.out.println(possibleSumDice(m,n,x));
}
}
}

reference :
practice.geeksforgeeks.org/problems/dice-throw