We are given a set of n countries that are engaged in trade with one another. For each country i, we have the value si of its budget surplus; this number may be positive or negative, with a negative number indicating a deficit. For each pair of countries i, j, we have the total value eij of all exports from i to j; this number is always nonnegative. We say that a subset S of the countries is free-standing if the sum of the budget surpluses of the countries in S, minus the total value of all exports from countries in S to countries not in S, is nonnegative. Give a polynomial-time algorithm that takes this data for a set of n countries and decides whether it contains a nonempty free-standing subset that is not equal to the full set.

Adrawing that places all lines parallel to the z axis at an angle from the horizon is 99 ! a. an oblique drawing b. a perspective drawing c. an auxiliary view d. a one-point perspective drawing

Can someone work out the answer as it comes up in one of my computer science exams and i don't understand the cryptovariables

What is the item which could be matched with a statement below? software installed on a computer that produces pop-up ads using your browser an example of social engineering malware loads itself before the os boot is complete type of spyware that tracks your keystrokes, including passwords windows key + l the practice of tricking people into giving out private information or allowing unsafe programs into the network or computer when someone who is unauthorized follows the employee through a secured entrance to a room or building a type of malware that tricks you into opening it by substituting itself for a legitimate program a computer that has been hacked, and the hacker is using the computer to run repetitive software in the background without the user's knowledge an infestation designed to copy itself repeatedly to memory, on drive space, or on a network