Codeforces 1186

A.

Water problem. slightly.

B. (Aborted)

You give a \ (n * m \) matrix, you can use \ (1 * 2 \) bricks covered matrix, but not a common side or the common point between the bricks required. Seeking up to put a few bricks.

solution

As long as this place seems to be:

<>.<>.^
......v
<>.<>..
......^
<>.<>.v

But have you ever considered \ (5 * 6 (ANS = 7) \) :

<>.^.^
...v.v
<>....
...^.^
<>.v.v

\ (6 * 6 (8 years =) \) :

<>.^.^
...v.v
<>....
....<>
^.^...
v.v.<>

\ (4 * 4 (= 4 years) \) :

<>.^
...v
^.<>
v...

It turns out that this question is no polynomial algorithm level, however, the data range of the original title is \ (10 ^ 9 \) , then this question was deleted, the game becomes unrated
std Wrong Answer

C.

Two strings of equal length 01 \ (S_1, S_2 \) , the definition of \ (f (s_1, s_2) \) of \ (s_1 [i] ≠ s_2 [i] \) a \ (I \) number . Given two strings 01 now \ (S, T (| S |> | T |) \) , seeking \ (S \) has a length equal to the number of \ (| T | \) substring \ (X \ ) satisfies \ (f (x, t) \) is even. \ ((| s |, | t | \ le 10 ^ 6) \)

solution

If \ (S_1 \) contains the number 1 and \ (S_2 \) contain the same number of a parity, then \ (f (s_1, s_2) \) is even, or odd.
Prefix and treatment. Time complexity \ (O (n-) \) .

D.

To give you a sequence of real numbers \ (A \) , are now trying to \ (A \) all the elements in the rounding up or down so that the sequences is zero. Ensure solvable. The output of a scheme.

solution

All elements of all let rounding down, then enough is applied to the elements is not an integer.
The title card precision and ceil() floor()caution. The best plus a eps.

E.