def can$\_$reconstitute$($s$,$ word$\_$set$)$:

n $=$ len$($s$)$

dp $=[$False$]*($n $+1)$

dp$[0]=$ True # Empty string is a valid sequence

for i in range$(1,$ n $+1)$:

for j in range$($i$)$:

# Check if dp$[$j$]$ is True and the substring s$[$j$+1...$i$]$ is a valid word

if dp$[$j$]$ and s$[$j:i$]$ in word$\_$set:

dp$[$i$]=$ True

break # If a valid word is found, no need to check further

return dp$[$n$]$

# Example usage:

s $=$ "itwasthebestoftimes"

word$\_$set $=\{"$it$",$ "was", "the", "best", $"$of$",$ "times"$\}$

result $=$ can$\_$reconstitute$($s$,$ word$\_$set$)$

if result:

print$("$The string can be reconstituted as a sequence of valid words."$)$

else:

print$("$The string cannot be reconstituted as a sequence of valid words."$)$ what is time complexity of this code result