Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You are given three non-negative integers, x, y, z. Your task is to find the smallest non-negative integer n with all of the following conditions:
- n\ {\rm mod}\ 17 = x
- n\ {\rm mod}\ 107 = y
- n\ {\rm mod}\ 1000000007(=10^9+7) = z
Constraints
- 0 \leq x < 17
- 0 \leq y < 107
- 0 \leq z < 10^9+7
Input
The input is given from Standard Input in the following format:
x y z
Output
Print the value of n in the statement.
Sample Input 1
15 50 1
Sample Output 1
1000000008
Sample Input 2
0 0 0
Sample Output 2
0
Sample Input 3
3 14 159265358
Sample Output 3
1050159272708
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
There are 1-, 5-, 10-, 50-, 100-, 500- yen coins, and you have an infinite number of coins of each type.
For a given positive integer x, let f(x) be the smallest number of coins you have to use to pay exactly x yen. For example, f(2018)= 9 because 2018 = 1 + 1 + 1 + 5 + 10 + 500 + 500 + 500 + 500.
You are given a positive integer N. Count the number of positive integers x such that f(x) = N.
Constraints
- 1 \leq N \leq 10^{18}
Input
Input is given from Standard Input in the following format:
N
Output
Print the number of positive integers x such that f(x) = N.
Sample Input 1
1
Sample Output 1
6
The value of x is 1, 5, 10, 50, 100, or 500.
Sample Input 2
2
Sample Output 2
19
The value of x is 2, 6, 11, 15, 20, 51, 55, 60, 101, 105, 110, 150, 200, 501, 505, 510, 550, 600, or 1000.
Sample Input 3
1000000000000000000
Sample Output 3
500
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You have a regular N-sided convex polygon. You are going to choose 3 or more vertices from the polygon, and make a new convex polygon P formed by chosen vertices. You very much like equiangular polygons (polygons whose vertex angles are all equal), so the polygon P must be equiangular.
Count the number of equiangular polygons that you can get in the above-mentioned way. Here, two polygons are considered to be the same if they are congruent, that is, one has the same shape and size as the other or as the mirror image of the other.
Constraints
- 3 \leq N \leq 10^{12}
Input
Input is given from Standard Input in the following format:
N
Output
Print the number of equiangular polygons that you can get.
Sample Input 1
6
Sample Output 1
3
You can get following 3 polygons.
Sample Input 2
10
Sample Output 2
4
You can get following 4 polygons.
Sample Input 3
1000000000000
Sample Output 3
749847411091
Time Limit: 5 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
First, you are given a positive integer MOD.
You have a knapsack, this is empty at first.
You have to perform Q queries.
- In each query, you have first to perform either
ADD
orREMOVE
operation, and then performFIND
operation. ADD
operation : You are given positive integers w, v. You put the cookie whose weight is w and whose value is v to the knapsack.-
REMOVE
operation : You take out the cookie with the smallest weight from the knapsack and eat it. -
FIND
operation : You are given non-negative integers l, r. You answer the following question:- Can you choose cookies from the knapsack so that the sum X of the weights of selected cookies satisfies l \leq (X\ {\rm mod}\ MOD) \leq r
- If you can't, output
-1
. - Otherwise, output the maximum sum of the values of selected cookies.
Constraints
- 2 \leq MOD \leq 500
- 1 \leq Q \leq 100,000
- 1 \leq w_i, v_i \leq 10^9
-
0 \leq l_i \leq r_i \leq MOD-1
-
The cookie given by an
ADD
operation is strictly heavier than any cookie which was added by a previousADD
operation. - When executing
REMOVE
operation, the knapsack isn't empty. - Queries are Online Query. Queries are encrypted as described later.
Input
Input is given from Standard Input in the following format:
MOD Q t'_1 w'_1 v'_1 l'_1 r'_1 t'_2 w'_2 v'_2 l'_2 r'_2 : t'_Q w'_Q v'_Q l'_Q r'_Q
-
0 \leq t'_i, w'_i, v'_i, l'_i, r'_1 \leq 2^{30} - 1
-
Queries are Online Query. You can get t_i, w_i, v_i, l_i, r_i by decoding t'_i, w'_i, v'_i, l'_i, r'_i.
-
t_i is query type.
- When t_i = 1, it involves
ADD
operation +FIND
operation. - When t_i = 2, it involves
REMOVE
operation +FIND
operation.
- When t_i = 1, it involves
-
When t_i = 2, you can assume that w_i=0 and v_i = 0.
Decryption
We prepare the decryption code with C++11 (or later), Java, D, C#.
Use class Crypto
for decryption, the code of class Crypto
is below.
C++
#include <cstdint> //uint8_t, uint32_t class Crypto { public: Crypto() { sm = cnt = 0; seed(); } int decode(int z) { z ^= next(); z ^= (next() << 8); z ^= (next() << 16); z ^= (next() << 22); return z; } void query(long long z) { const long long B = 425481007; const long long MD = 1000000007; cnt++; sm = ((sm * B % MD + z) % MD + MD) % MD; seed(); } private: long long sm; int cnt; uint8_t data[256]; int I, J; void swap_data(int i, int j) { uint8_t tmp = data[i]; data[i] = data[j]; data[j] = tmp; } void seed() { uint8_t key[8]; for (int i = 0; i < 4; i++) { key[i] = (sm >> (i * 8)); } for (int i = 0; i < 4; i++) { key[i+4] = (cnt >> (i * 8)); } for (int i = 0; i < 256; i++) { data[i] = i; } I = J = 0; int j = 0; for (int i = 0; i < 256; i++) { j = (j + data[i] + key[i%8]) % 256; swap_data(i, j); } } uint8_t next() { I = (I+1) % 256; J = (J + data[I]) % 256; swap_data(I, J); return data[(data[I] + data[J]) % 256]; } };
Java
public class Main { public static class Crypto { public Crypto() { sm = cnt = 0; seed(); } public int decode(int z) { z ^= next(); z ^= (next() << 8); z ^= (next() << 16); z ^= (next() << 22); return z; } public void query(long z) { final long B = 425481007; final long MD = 1000000007; cnt++; sm = ((sm * B % MD + z) % MD + MD) % MD; seed(); } long sm; int cnt; byte data[] = new byte[256]; int I, J; int asUint(byte x) { int y = x; return y & 0xff; } void seed() { byte key[] = new byte[8]; for (int i = 0; i < 4; i++) { key[i] = (byte)(sm >>> (i * 8)); } for (int i = 0; i < 4; i++) { key[i+4] = (byte)(cnt >>> (i * 8)); } for (int i = 0; i < 256; i++) { data[i] = (byte)i; } I = J = 0; int j = 0; for (int i = 0; i < 256; i++) { j = (j + asUint(data[i]) + asUint(key[i % 8])) % 256; byte tmp = data[i]; data[i] = data[j]; data[j] = tmp; } } int next() { I = (I+1) % 256; J = (J+asUint(data[I])) % 256; byte tmp = data[I]; data[I] = data[J]; data[J] = tmp; return asUint(data[(asUint(data[I]) + asUint(data[J])) % 256]); } } public static void main(String[] args) { ... } }
D
class Crypto { public: this() { sm = cnt = 0; seed(); } int decode(int z) { z ^= next(); z ^= (next() << 8); z ^= (next() << 16); z ^= (next() << 22); return z; } void query(long z) { immutable static long B = 425481007; immutable static long MD = (10^^9)+7; cnt++; sm = ((sm * B % MD + z) % MD + MD) % MD; seed(); } private: import std.algorithm : swap; long sm; int cnt; ubyte[256] data; int I, J; void seed() { ubyte[8] key; foreach (i; 0..4) { key[i] = cast(ubyte)(sm >> (i*8)); } foreach (i; 0..4) { key[i+4] = cast(ubyte)(cnt >> (i*8)); } foreach (i; 0..256) { data[i] = cast(ubyte)(i); } I = J = 0; int j = 0; foreach (int i; 0..256) { j = (j + data[i] + key[i%8]) % 256; swap(data[i], data[j]); } } ubyte next() { I = (I+1) % 256; J = (J + data[I]) % 256; swap(data[I], data[J]); return data[(data[I] + data[J]) % 256]; } }
C#
class Crypto { public Crypto() { sm = cnt = 0; data = new byte[256]; seed(); } public int decode(int z) { z ^= next(); z ^= (next() << 8); z ^= (next() << 16); z ^= (next() << 22); return z; } public void query(long z) { const long B = 425481007; const long MD = 1000000007; cnt++; sm = ((sm * B % MD + z) % MD + MD) % MD; seed(); } long sm; int cnt; byte[] data; int I, J; void seed() { byte[] key = new byte[8]; for (int i = 0; i < 4; i++) { key[i] = (byte)(sm >> (i*8)); } for (int i = 0; i < 4; i++) { key[i+4] = (byte)(cnt >> (i*8)); } for (int i = 0; i < 256; i++) { data[i] = (byte)i; } I = J = 0; int j = 0; for (int i = 0; i < 256; i++) { j = (j + data[i] + key[i%8]) % 256; byte tmp = data[i]; data[i] = data[j]; data[j] = tmp; } } byte next() { I = (I+1) % 256; J = (J + data[I]) % 256; byte tmp = data[I]; data[I] = data[J]; data[J] = tmp; return data[(data[I] + data[J]) % 256]; } }
The procedure of decrypto:
- First, you make an instance of
class Crypto
. - In each query,
- call the
decode
function for each of t', w', v', l', r' in order. The return values are t, w, v, l, r. - call the
query
function with the result of theFIND
operation.
- call the
The sample code of C++ is below.
#include <cstdio> #include <cstdlib> #include <cstdint> //uint8_t, uint32_t class Crypto { ... }; int main() { int MOD, Q; scanf("%d %d", &MOD, &Q); Crypto c; for (int i = 0; i < Q; i++) { int t, w, v, l, r; scanf("%d %d %d %d %d", &t, &w, &v, &l, &r); t = c.decode(t); w = c.decode(w); v = c.decode(v); l = c.decode(l); r = c.decode(r); if (t == 1) { (add candy(w, v)) } else { (delete candy) } long long ans = (answer for query(l, r)); c.query(ans); printf("%lld\n", ans); } }
The sample codes of Java, D, C# are below.
Java
import java.io.PrintWriter; import java.util.Scanner; public class Main { public static class Crypto { ... } public static void main(String[] args) { Scanner in = new Scanner(System.in); //!!warning!! : Java's scanner is slow PrintWriter out = new PrintWriter(System.out); int MOD = in.nextInt(); int Q = in.nextInt(); Crypto c = new Crypto(); for (int i = 0; i < Q; i++) { int t, w, v, l, r; t = c.decode(in.nextInt()); w = c.decode(in.nextInt()); v = c.decode(in.nextInt()); l = c.decode(in.nextInt()); r = c.decode(in.nextInt()); if (t == 1) { (add candy(w, v)) } else { (delete candy) } long ans = (answer for query(l, r)); c.query(ans); out.println(ans); } out.flush(); } }
D
class Crypto { ... } int main() { import std.stdio; int MOD, Q; readf("%d\n%d\n", &MOD, &Q); Crypto c = new Crypto(); foreach (i; 0..Q) { int t, w, v, l, r; readf("%d %d %d %d %d\n", &t, &w, &v, &l, &r); t = c.decode(t); w = c.decode(w); v = c.decode(v); l = c.decode(l); r = c.decode(r); if (t == 1) { (add candy(w, v)) } else { (delete candy) } long ans = (answer for query(l, r)); c.query(ans); writeln(ans); } return 0; }
C#
using System; using System.IO; class Crypto { ... } class Myon { static void Main() { var writer = new StreamWriter(Console.OpenStandardOutput()){AutoFlush = false}; //fast writer Console.SetOut(writer); int MOD = int.Parse(Console.ReadLine()); int Q = int.Parse(Console.ReadLine()); Crypto c = new Crypto(); for (int i = 0; i < Q; i++) { var inputs = Console.ReadLine().Split(' '); int t, w, v, l, r; t = c.decode(int.Parse(inputs[0])); w = c.decode(int.Parse(inputs[1])); v = c.decode(int.Parse(inputs[2])); l = c.decode(int.Parse(inputs[3])); r = c.decode(int.Parse(inputs[4])); if (t == 1) { (add candy(w, v)) } else { (delete candy) } long ans = (answer for query(l, r)); c.query(ans); Console.WriteLine(ans); } Console.Out.Flush(); } }
Remark:
- You don't need to find vulnerability of this encryption.
class Crypto
consume time at most about 200 ms when Q = 100,000.
Output
Print results of FIND
operation, one per line.
Sample Input 1
10 7 281614559 249378726 433981056 466775634 683612866 727071329 787572584 591471796 328464426 757737734 279580343 240336097 538846427 808491898 224313807 222498984 42804452 371605808 667115067 791865961 68683864 1045549765 515479514 1067782238 349547144 907343711 381772625 149003422 879314974 953881571 883899098 700164610 414212891 752949213 972845634
Sample Output 1
10 0 -1 21 -1 11 111
The result of decoding this input is as follows.
10 7 1 5 10 5 5 2 0 0 0 9 1 7 10 2 4 1 12 11 9 9 2 0 0 1 1 1 22 10 2 3 1 32 100 4 4
Knapsack | Selected Cookies |
---|---|
(w, v) = {(5, 10)} | {(5, 10)} |
{} | {} |
{(7, 10)} | -1 |
{(7, 10), (12, 11)} | {(7, 10), (12, 11)} |
{(12, 11)} | -1 |
{(12, 11), (22, 10)} | {(12, 11)} |
{(12, 11), (22, 10), (32, 100)} | {(12, 11), (32, 100)} |
Sample Input 2
7 20 281614559 249378726 433981094 466775639 683612870 59536386 999828879 241246766 434670565 174365647 172060134 848462699 857413429 182122460 807914643 808426426 600772095 829463884 974102196 354283529 370037909 1024921880 664216868 194331103 140834169 917331875 242953442 205247688 335469789 1055568137 823475244 641321246 617915164 160300810 1073617378 892669150 939175632 904628449 606339993 1059849410 829170894 436718235 288920513 228195002 55212938 772189413 373108543 94133155 610930061 513937768 986619331 175674265 812546186 865335970 605634588 880196843 1071068047 723408215 587598264 380801783 393196081 141080294 584230885 135343295 661927186 5740819 967233824 22597607 888639499 467454437 365679801 515258603 989059385 962028117 761163096 357270919 737051059 569528959 935653628 70506031 869282414 947492121 280522456 96822010 856514221 155948699 826430734 291243254 381421299 617876780 980891674 833928389 1048677341 522527723 223764850 50617939 963598173 281959650 499436870 47455938
Sample Output 2
0 134 90 158 -1 22 238 269 179 189 121 53 41 41 -1 58 -1 84 -1 149
The result of decoding this input is as follows.
7 20 1 5 44 0 1 1 11 90 0 3 2 0 0 3 4 1 18 68 1 6 1 25 32 2 3 1 31 22 2 3 1 32 26 1 5 1 36 31 3 6 2 0 0 2 5 1 43 10 3 6 2 0 0 5 6 2 0 0 3 4 2 0 0 2 4 2 0 0 1 5 2 0 0 3 5 1 49 48 0 4 2 0 0 1 5 1 50 36 0 6 1 56 48 3 5 1 59 17 3 5
Time Limit: 3 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
Ao loves certain sets of non-negative integers.
Let X be a set of non-negative integers. Whether she loves X or not is determined as follows:
- If X is the empty set, she loves X.
- If, for any (possibly the same) two elements u and v in X, at least one of u+v and {\rm abs}(u-v) is contained in X, she loves X.
- If none of the above conditions is satisfied, she does not love X.
You are a big fan of Ao, and going to present her a set of non-negative integers. Currently you have a set A of non-negative integers. You want to erase (possibly zero) elements from A so that she loves the set of remaining integers. You also want to maximize the number of remaining integers. What is the largest number of remaining integers?
Constraints
- A is not empty.
- The largest element in A is not larger than 500,000
Input
Input is given from Standard Input in the following format:
S
Here, S=S_0S_1...S_{|S|-1} is the string which indicates A.
For each i ( 0 \leq i \leq |S|-1 ), S_i = 1
if A contains i and S_i = 0
if not.
It is guaranteed that S_{|S|-1} is 1
.
Output
Print the largest number of remaining integers.
Sample Input 1
1000001001011
Sample Output 1
3
The set A = \{0,6,9,11,12\}. If you erase 9 and 11, Ao loves the set of remaining integers: \{0,6,12\}.
Sample Input 2
10110110101
Sample Output 2
4
Sample Input 3
0111
Sample Output 3
0
The set of remaining integers must be empty.
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
Takahashi-kun sends integer sequences to Aoki-kun every year as his birthday present. But in this year, Takahashi-kun plans to send sequences of points on a two-dimensional plane to Aoki-kun.
Firstly, he makes 3 point sequences: (a_0, a_1, ..., a_{N-1}), (b_0, b_1, ..., b_{N-1}), and (c_0, c_1, ..., c_{N-1}), and makes a point d_0. Then he makes the points d_1, d_2, ..., d_N in this order as follows:
- For each i = 0, 1, ..., {N-1}, d_{i+1} is defined as the intersection point of two lines: the line that passes through a_i and b_i, and the line that passes through c_i and d_i.
It can happen that a point d_{i+1} can not be defined for some i. For example, when two lines are the same, there are an infinite number of intersection points.
Takahashi-kun wants to know the smallest i such that d_{i+1} can not be defined. To be precise, d_{i+1} can not be defined if either of the following conditions is met.
- c_i = d_i
- two lines given by a_i, b_i, c_i, and d_i are the same, or parallel.
It is guaranteed that a_i \neq b_i for all i.
Note that, in the following sections, x- and y- coordinates of a point p are denoted as p.x and p.y, respectively.
Constraints
- 1 \leq N \leq 100,000
- |a_i.x|, |a_i.y|, |b_i.x|, |b_i.y|, |c_i.x|, |c_i.y| \leq 1,000
- |d_0.x|, |d_0.y| \leq 1000
- a_i \neq b_i
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
N d_0.x d_0.y a_0.x a_0.y b_0.x b_0.y c_0.x c_0.y a_1.x a_1.y b_1.x b_1.y c_1.x c_1.y : a_{N-1}.x a_{N-1}.y b_{N-1}.x b_{N-1}.y c_{N-1}.x c_{N-1}.y
Output
Print the smallest i such that d_{i+1} can not be defined. If all points are defined, print N.
Sample Input 1
6 0 0 10 -10 10 10 10 0 0 10 20 10 10 10 0 -10 0 -100 0 10 0 0 0 -100 0 0 0 0 0 1 0 0 31 14 15 92 65 35
Sample Output 1
3
Sample Input 2
11 0 0 299 0 299 1 3 1 1 0 1 1 300 100 299 0 299 1 3 1 1 0 1 1 300 100 299 0 299 1 3 1 1 0 1 1 300 100 299 0 299 1 3 1 1 0 1 1 300 100 299 0 299 1 3 1 1 0 1 1 300 100 0 0 3 1 3 1
Sample Output 2
10
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You have Q triangles, numbered 1 through Q.
The coordinates of the vertices of the i-th triangle are (x_{i1}, y_{i1}), (x_{i2}, y_{i2}) and (x_{i3}, y_{i3}) in counterclockwise order. Here, x_{i1}, x_{i2}, x_{i3}, y_{i1}, y_{i2} and y_{i3} are all integers.
For each triangle, determine if there exists a grid point contained in its interior (excluding the boundary). If it exists, construct one such point.
Constraints
- All input values are integers.
- 1 \leq Q \leq 10 000
- 0 \leq x_{i1}, x_{i2}, x_{i3}, y_{i1}, y_{i2}, y_{i3} \leq 10^9
- (x_{i1}, y_{i1}), (x_{i2}, y_{i2}) and (x_{i3}, y_{i3}) are in counterclockwise order.
- The areas of the triangles are not 0.
Input
Input is given from Standard Input in the following format:
Q x_{11} y_{11} x_{12} y_{12} x_{13} y_{13} x_{21} y_{21} x_{22} y_{22} x_{23} y_{23} : x_{Q1} y_{Q1} x_{Q2} y_{Q2} x_{Q3} y_{Q3}
Output
Output should contain Q lines.
In the i-th line, if there is no grid point contained in the interior (excluding the boundary) of the i-th triangle, print -1 -1
.
If it exists, choose one such grid point, then print its x-coordinate and y-coordinate with a space in between.
Sample Input 1
4 1 7 3 5 5 7 1 4 1 2 5 4 6 1 7 1 7 6 11 3 11 4 8 5
Sample Output 1
3 6 2 3 -1 -1 10 4
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You are given a string S consisting of lowercase English letters. Count the number of strings T that satisfies all of the following conditions:
- T is a string of the same length as S, consisting of lowercase English letters.
- For all K ( 1 \leq K \leq |S| ), the string formed by the first K letters of S does not coincide with the string formed by the last K letters of T.
Since the answer can be very large, find the number modulo 10^9+7.
Constraints
- 1 \leq |S| \leq 10^6
- S consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
S
Output
Print the number of strings that satisfy the condition, modulo 10^9+7.
Sample Input 1
aa
Sample Output 1
650
For example, T= zz
and ab
satisfy the condition, but ba
or aa
does not.
Sample Input 2
abc
Sample Output 2
16873
Sample Input 3
xrxbaxrxikxrxgvcpuwx
Sample Output 3
352084595
Time Limit: 3 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You are given an integer sequence a_0, a_1, ..., a_{N-1}.
You have to perform Q queries, each query is one of the following:
ADD QUERY(t=0 l r x)
: for each i between l and r, inclusive, replace a_i with a_i + x.DIV QUERY(t=1 l r x)
: for each i between l and r, inclusive, replace a_i with {\rm floor}(a_i / x), where {\rm floor}(y) is the biggest integer that is not greater than y.MAX QUERY(t=2 l r x=0)
: print {\rm max}(a_l, a_{l+1}, ..., a_r).RESTORE QUERY(t=3 l r x=0)
: for each i between l and r, inclusive, set a_i to the initial value of a_i, that is, the value given in the input.
Constraints
- All input values are integers.
- 1 \leq N, Q \leq 200,000
- 0 \leq a_i \leq 10^8
- t_i = 0, 1, 2, 3
- 0 \leq l_i \leq r_i \leq N-1
- 1 \leq x_i \leq 1000(when t_i \neq 2, 3)
Input
Input is given from Standard Input in the following format:
N Q a_0 a_1 ... a_{N-1} t_1 l_1 r_1 x_1 t_2 l_2 r_2 x_2 : t_Q l_Q r_Q x_Q
Output
For each MAX QUERY
, print {\rm max}(a_l, a_{l+1}, ..., a_r), one per line.
Sample Input 1
5 9 1 2 3 4 5 2 0 4 0 0 0 1 10 2 0 4 0 2 2 2 0 1 0 1 4 2 0 0 0 2 1 1 0 3 0 4 0 2 0 1 0
Sample Output 1
5 12 3 2 3 2
- {\rm max}(1, 2, 3, 4, 5) = 5
- 1, 2, 3, 4, 5 → 11, 12, 3, 4, 5
- {\rm max}(11, 12, 3, 4, 5) = 12
- {\rm max}(3) = 3
- 11, 12, 3, 4, 5 → 2, 3, 3, 4, 5
- {\rm max}(2) = 2
- {\rm max}(3) = 3
- The array is restored to 1, 2, 3, 4, 5
- {\rm max}(1, 2) = 2
Sample Input 2
4 7 0 1 0 1 2 0 3 0 0 0 3 1 1 0 3 2 2 0 3 0 0 0 3 1 1 0 3 2 2 0 3 0
Sample Output 2
1 1 1
Sample Input 3
10 23 13 1 22 8 28 18 23 9 22 27 1 3 4 5 1 8 8 8 0 3 9 5 0 2 6 3 3 0 4 0 1 1 3 7 2 2 2 0 2 3 5 0 0 1 4 2 3 0 9 0 2 0 1 0 0 3 9 8 2 1 9 0 0 8 9 5 1 5 7 7 0 3 5 7 0 7 9 7 3 3 6 0 2 1 6 0 0 1 1 7 1 4 8 10 2 0 9 0 1 5 6 1
Sample Output 3
3 28 13 36 28 47
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You have a string s=s_0s_1...s_{N-1} of length N consisting of A
and B
.
You have to process Q queries.
Consider the i-th query ( 1 \leq i \leq Q ).
In this query you are given integers l_i and r_i.
Then, for each x ( l_i \leq x \leq r_i ), s_x is changed to the other letter, that is, A
becomes B
and B
becomes A
.
After each query, you have to calculate f(B
+ s + A
).
Here, f(t) is a function which, given a string t, returns a non-negative integer.
The value of f(t) is defined as follows:
- Consider the following step.
- Step: For all substrings of t which coincide with
BA
, replace them withAB
. All replacements are done at the same time.
- Step: For all substrings of t which coincide with
- f(t) is the number of steps you need to perform until no substring of t coincides with
BA
.
For example, f(ABAB
) = 1, f(BBAA
) = 3, and f(AAA
) = 0.
Constraints
- 1 \leq N \leq 200000
- |s| = N
- s consists of
A
andB
. - 1 \leq Q \leq 200000
- 0 \leq l_i \leq r_i \leq N-1
- N,Q,l_i,r_i are integers.
Input
Input is given from Standard Input in the following format:
N s Q l_1 r_1 l_2 r_2 : l_Q r_Q
Output
After each query, print the value of f(B
+ s + A
), one per line.
Sample Input 1
5 BAABA 2 1 3 0 2
Sample Output 1
6 6
After the first query, the string s is BBBAA
, so print the value of f(BBBBAAA
) in the first line.
After the second query, the string s is AAAAA
, so print the value of f(BAAAAAA
) in the second line.
Sample Input 2
1 A 2 0 0 0 0
Sample Output 2
2 2
Time Limit: 2 sec / Memory Limit: 1024 MB
Score : 100 points
Problem Statement
You are given three integers N, A, and B.
Let P=(P_0,P_1,...,P_{N-1}) be a permutation of (0,1,...,N-1). P is said good if and only if it satisfies all of the following conditions:
- The length of a longest increasing subsequence of P is at most 2.
- P_A = B
Count the number of good permutations modulo 10^9+7.
Constraints
- 1 \leq N \leq 10^6
- 0 \leq A \leq N-1
- 0 \leq B \leq N-1
Input
Input is given from Standard Input in the following format:
N A B
Output
Print the number of good permutations modulo 10^9+7.
Sample Input 1
3 0 0
Sample Output 1
1
The only good permutation is (0,2,1).
Sample Input 2
12 2 3
Sample Output 2
5390
Sample Input 3
10000 9875 5431
Sample Output 3
135608808