A spy and his four messages

Question

A spy has been allotted a task of following a man (innocent until proved guilty) around the world. The spy's boss does not trust anyone in the office, so they decide to exchange messages in an encrypted form which only they understand.

The spy follows the man and sends his location to his boss in an encrypted form which only his boss will be able to decipher.

Following the man in four different cities in four different countries the spy sends the following four messages to his boss.

Message 1:
Standing in front of a giant building
1 man and 2 women came out, all three together, 2 men and 2 women came out, all four together, 1 woman and 1 man came out separately, 2 never seen before twin women went in

Message 2:
Standing in front of atomic towers
1 couple came out, 1 woman and 1 man came out separately, 1 couple came out

Message 3:
Standing in front of a cylinder booth
1 man, 1 woman, 1 man came out, all three separately, 1 woman, 2 men came out, all three together, never seen twin women went in

Message 4:
Standing in front of a bookshop
2 men came out separately, 1 couple came out, 2 sets of twin men went in

The office staff is indeed not trustworthy, they leaked the messages, can you decipher and identify the locations?

Answer 1

The spy has sent locations from:

London, Moscow, Barcelona and Hong Kong.

How does the code work?

The first sentence in each message describes a location. Take this location as starting point.

Next, remove letters. Which letters to remove is encoded in the number and sex of the people who leave and enter the location. Men are consonants and women are vowels. (Y is a consonant).

When they leave together, the letters form a contiguous block in the word. When they leave separately, there is at least one letter between the letters that are removed. A couple refers to a consonant and a vowel in arbitrary order. The directives are carried out left to right. In other words the letters removed by the second sentence are to the right of those removed by the first sentence.

Then, add letters according to how many and which people enter. If a letter hasn't been seen before, it wasn't present in the original word.

Finally, anagram the word to get the name of a city.

Here's how it works for each message:

‹gia›nt building → n‹t bui›lding → n ld‹i›n‹g› → (n ldn + oo)✻ → LONDON
‹at›omic towers → om‹i›c ‹t›owers → omc ow‹er›s → (omc ows)✻ → MOSCOW
c‹y›l‹i›n‹d›er booth → clner bo‹oth› → (clner bo + aa)✻ → BARCELONA
‹b›ook‹s›hop → ookh‹op› → (ookh + nn + gg)✻ → HONG KONG