Function to fill the prefix_sum [ ] with the prefix sum of the given array
def findPrefixSum ( arr , n ) : NEW_LINE INDENT prefix_sum [ 0 ] = arr [ 0 ] ; NEW_LINE for i in range ( n ) : NEW_LINE INDENT prefix_sum [ i ] = arr [ i ] + prefix_sum [ i - 1 ] ; NEW_LINE DEDENT DEDENT