bzoj-2038: [2009 countries Training team] small Z socks (hose)

Title Link: http://www.lydsy.com/JudgeOnline/problem.php?id=2038

MO team algorithm can solve a class of non-modified, offline query problems. And this problem can be done with Mo team.

* I was reading this paper learned: (link ~)

In fact, the team is a kind of optimization of violence, just the query is offline pre-ordered according to the rules, and then the violence to deal with these questions in turn.

There are two ways to do this and only write a segmented solution at this time. First the 1~n is divided into sqrt (n), u = sqrt (n), and M queries are sorted by the first block and then by R.

The code is as follows:

　

1#include <iostream>2#include <cstdio>3#include <cstring>4#include <algorithm>5#include <cmath>6 7 using namespacestd;8 Const intMAXN = 5e4 +5;9typedefLong LongLL;Ten intA[MAXN], u, CONT[MAXN]; One structque { A     intL, R, id; - }Q[MAXN]; - structData { the LL x, y; - }ANS[MAXN]; -  - ll GCD (ll X, ll y) { +     if(!y) -         returnx; +     returnGCD (y, x%y); A } at  - BOOLcmp (que x, que y) { -     if(x.l/u = = Y.L/u) -         returnX.R <Y.R; -     returnx.l/u < Y.L/u; - } in  - inline ll F (ll X) { to     returnX *x; + } -  the intMain () * { $     intN, M;Panax Notoginseng      while(~SCANF ("%d%d", &n, &m)) { -          for(inti =1; I <= N; i++) { thescanf"%d", A +i); +         } A          for(inti =1; I <= m; i++) { thescanf"%d%d", &AMP;Q[I].L, &Q[I].R); +Q[i].id =i; -         } $U =sqrt (n); $Sort (q +1, q + M +1, CMP); -         intL =1, R =0; -LL temp =0; thememset (cont,0,sizeof(cont)); -          for(inti =1; I <= m; i++) {Wuyi              while(L <Q[I].L) { theTemp-=f (Cont[a[l]]); -cont[a[l]]--; WuTemp + =f (Cont[a[l]]); -l++; About             } $              while(L > Q[I].L) {//the front is still not counted. -l--; -Temp-=f (Cont[a[l]]); -cont[a[l]]++; ATemp + =f (Cont[a[l]]); +             } the              while(R >Q[I].R) { -Temp-=f (Cont[a[r]]); $cont[a[r]]--; theTemp + =f (Cont[a[r]]); ther--; the             } the              while(R <Q[I].R) { -r++; inTemp-=f (Cont[a[r]]); thecont[a[r]]++; theTemp + =f (Cont[a[r]]); About             } theans[q[i].id].x = Temp-(r-l +1); theAns[q[i].id].y = (LL) (R-l +1) * (R-L); the         } +          for(inti =1; I <= m; i++) { -             if(!ans[i].x | |!ans[i].y) { theprintf"0/1\n");Bayi             } the             Else { thetemp =gcd (ans[i].x, ans[i].y); -printf"%lld/%lld\n", Ans[i].x/temp, ANS[I].Y/temp); -             } the         } the     } the}

bzoj-2038: [2009 countries Training team] small Z socks (hose)