Triangle

class Solution:
    def minimumTotal(self, triangle: List[List[int]]) -> int:
        x=len(triangle)
        if(x==1):
            return triangle[0][0]
        elif(x==2):
            return min(triangle[1][0],triangle[1][1])+triangle[0][0]
        #print(x)
        ans=[]
        def bt(l1,l2,pos,ans,level,x,cur):
            #print(l1,l2,pos,level)
            if(level==(x-1)):
                ans.append(sum(cur)+l1)
                ans.append(sum(cur)+l2)
                return
            bt(triangle[level+1][pos],triangle[level+1][pos+1],pos,ans,level+1,x,cur+[l1])
            bt(triangle[level+1][pos+1],triangle[level+1][pos+2],pos+1,ans,level+1,x,cur+[l2])
        bt(triangle[1][0],triangle[1][1],0,ans,1,x,[])
        return min(ans)+triangle[0][0]