BZOJ 3758 data segments

BZOJ 3758 data segments

Calculate the number of beautiful numbers in the [l, r] range. The beautiful number is defined as the number between [0, 9] obtained by dividing the decimal number into two groups, and the number is equal.

Train of Thought: in fact, the first time I heard that I was rejected when I was asked to create a table, because you couldn't ask me to do it, so I would like to do it right away. First, I would like to give it a try, because I don't want to go back to the cheat when I finish it. The Code "Submit" is very short and very small. In this way, the OIer will scold me and there is no such table at all, it proves that the above is false. Later, I also confirmed that this table is indeed usable. My classmates played it for about two minutes and I felt pretty good. Later, I asked them not to cheat when I played it, because I want OIer to see what it looks like after I finish it, and it will look like it after you finish it!

...

It's good to create a big table. If you have such questions, you must think about whether you can make a table or not. If you are lucky, you can get a full score. First, the data range is too large, so you cannot directly create all tables. Therefore, we need to associate the tabulation with brute force. We create a table for a block based on 5000000, and the code won't be long. Then the rest of the code can be violent.

I don't know if I can pass the brute-force backpack, but I can see that Shen Peng uses a binary optimization backpack, and the constant is very small, so it is also used.

CODE:

#include 
 
  #include 
  
   #include 
   
    #include #define BLOCK 5000000using namespace std;int num[] = {0,2196800,4366880,6782004,9182258,11590745,13996047,16403907,18810719,21199399,23601310,26006639,28401296,30780453,33151141,35517685,37865237,40194471,42514127,44818223,47111407,49526531,51926786,54395976,56858336,59346650,61832643,64321881,66811192,69295186,71781713,74267457,76751555,79230464,81704149,84170195,86626601,89074946,91513942,93959345,96400455,98808942,101214244,103702558,106188552,108643571,111104170,113592810,116080738,118549357,121025141,123509319,125991518,128456408,130927549,133393411,135853348,138306327,140761869,143209568,145654892,148062752,150469564,152958802,155448113,157936753,160424682,162870479,165316242,167797533,170282583,172764227,175244787,177698265,180151503,182627144,185104838,187569465,190034891,192474367,194913068,197301748,199703659,202187653,204674180,207142799,209618583,212099874,214584925,217007522,219446727,221919701,224393574,226859775,229333643,231805293,234281777,236714686,239165608,241610353,244056062,246461391,248856048,251341792,253825890,256310068,258792267,261273911,263754471,266227445,268701319,271155956,273606213,276086573,278564272,281035883,283502662,285965530,288427696,290873607,293317366,295696523,298067211,300546120,303019805,305484695,307955836,310409314,312862552,315328753,317802621,320282981,322760681,325172415,327585453,330052161,332510934,334957902,337405293,339842143,342276694,344643238,346990790,349456836,351913242,354379104,356839041,359314682,361792376,364264026,366740510,369212121,371678900,374145608,376604382,379003316,381388631,383833355,386266143,388702239,391130374,393459608,395779264,398227609,400666605,403119584,405575126,408039753,410505179,412938088,415389010,417851878,420314044,422761012,425208403,427653127,430085916,432434127,434779290,437207061,439626259,441930355,444223539,446668942,449110052,451557751,454003075,456442551,458881252,461325997,463771706,466217617,468661376,471098226,473532777,475968873,478397008,480824779,483243978,485561378,487875963};inline bool Judge(int x){int sum = 0;for(int i = x; i; i /= 10)sum += (i % 10);if(sum&1)return false;long long f = 1;for(int i = x; i; i /= 10)f |= (f << (i % 10));return f&(1LL << sum / 2);}inline int Ask(int x){int p = x / BLOCK;int re = num[p];for(int i = p * BLOCK + 1; i <= x; ++i)re += Judge(i);return re;}int main(){int x,y;cin >> x >> y;cout << Ask(y) - Ask(x - 1) << endl;return 0;}