Algorithm for finding all paths in a NxN grid

Question

Imagine a robot sitting on the upper left hand corner of an NxN grid. The robot can only move in two directions: right and down. How many possible paths are there for the ro

Answer 1

int N;
function num_paths(intx,int y)
{
    int[][] arr = new int[N][N];
arr[N-1][N-1] = 0;
for(int i =0;i=0;i--)
{
    for(int j=N-2;j>=0;j--)
    {
        arr[i][j]= arr[i+1][j]+arr[i][j+1];
    }
}
return arr[0][0];
 }