Consider a string, s, that is a series of characters, each followed by its frequency as an integer. the string is not compressed correctly, so there may be many occurrences of the same character. a properly compressed string will consist of one instance of each character in alphabetical order followed by the total count of that character within the string. for example, the string a3c9b2c1 has two instances where ‘c’ is followed by a count: once with 9 occurrences, and again with 1. it should be compressed to a3b2c10.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

What is the major difference between thermoplastics and thermosetting plastics from the polymerization structure point of view?

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.