Give a characterization, in terms of n, of the running time of the following four functions:

def examplel (1st): """Return the sum of the prefix sums of sequence S."" n = len (1st) total 0 for j in range(n): for k in range (1+j): total += lst[k] return total def example2 (1st): "Return the sum of the prefix sums of sequence s." n = len (1st) prefix = 0 total 0 for j in range (n): prefix += lst[j] total += prefix return total = def example3 (n): i = 1 sum = 0 while (i 1): for j in range(i): sum += i*j i //= 2 return sum