Unique Paths

use dynamic programming to exchange time with space.

public class Solution {
    public int uniquePaths(int m, int n) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        int[][] mytable = new int[m+1][n+1];
        
        return getpath(m, n, mytable);
        
    }
    
    public int getpath(int m, int n, int[][] table)
    {
        if(m <= 1 || n <= 1)
            return 1;
        if(table[m][n] > 0)
            return table[m][n];
        table[m][n] = getpath(m-1, n, table) + getpath(m, n-1, table);
        return table[m][n];
    }
}