PYTHON class BinarySearch: def erfen(self,ls,left,right,val): if left <= right: mid = (left + right) // 2 if val == ls[mid]: return mid elif val < ls[mid]: return self.erfen(ls, left, mid-1, val) else: return self.erfen(ls,mid+1,right,val) else: return -1 def getPos(self, A, n, val): # write c...