Codeforces 154 div2

Question A: greedy. If the number of people in a gender is small and the number of people is small. Copy the file directly during the competition .. After changing n to m, the game data will lag behind. = !!

Question B: directly divide the two points and locate the number greater than the current 2 * CI. Counts the number of erased sides .. Find the minimum value from all results.

Question C: BFs .. Understand the question, common BFs. The key is to jump up and down, with a little special. The result is 0 if R1 = R2 & C1 = c2 .. This question is also kneeling.

D: enumeration boundary. During the competition, Hu wrote an enumeration at the top left and the bottom right of the enumeration.Algorithm.. So many points must have timed out. In fact, this is to count the number of matrix A from () to (I, j) in C [I] [J. Simply DP.

Then enumerate the left and right sides or upper and lower boundary. If it is to enumerate the left and right borders, and then loop up and down borders, then the enumeration will get two vertices, if the two vertices are equal. Find the same number of boundary letters (the boundary above this bottom boundary), and add ans.

Question E: I have no time to watch the game.