Tree-like array maintenance interval max

When the interval is summed, we only need the[1, R], < Span class= "Mopen" >[1,l 1 [l,r] " and.

But the interval maximum does not satisfy this property.

We can split the interval [l,R] into several sub-ranges, and then merge the answers.

Drawing shows thatmax_i needs max only max_{i-2^0}, max_{i-2^1}, max_{i-2^2} ... max_{i-lowbit (i) +1}.

Modify

void Change (int  r) {    = a[r];      for (int11)         = Max (C[r], c[r-i]);}

Enquiry

We're looking for[L, R]is the maximum value of the sub-interval.Max, that is, decrementsR, there can be an optimization, that is, when you find aMax_i< Span class= "Reset-textstyle scriptstyle cramped mtight" > ?,  < Span class= "Katex-mathml" >i? Lowbi< Span class= "Mord mathit" >t (i) ≥l , more

new, i = I-lowbit (i) < Span class= "Mord mathit" > l>r  just jump out of the loop.

int getmax (intint  r) {    int ret = a[r];      while (l <= r) {        = max (ret, a[r]);          for (--r; r-l >= lowbit (R); R-= Lowbit (r)            ) = Max (ret, c[r]);    }     return ret;}

 

It should be noted that it only supports end-of-insertion and does not support single-point modification operations.

#include <iostream>#include<stdio.h>#include<memory.h>using namespacestd;inta[200005];intc[200005];intLowbit (intx) {    returnx& (-x);}voidUpdateintx) {C[x]=A[x];  for(intI=1; I<lowbit (x); i<<=1) C[x]=max (c[x],c[x-i]);}intQueryintLintR) {    intans=A[r];  while(l<=R) {ans=Max (Ans,a[r]);  for(--r; R-l>=lowbit (r); r-=Lowbit (R)) Ans=Max (Ans,c[r]); }    returnans;}intMain () {intm,d; scanf ("%d%d",&m,&d); intCNT =0, t=0;  for(inti =0; i<m; i++)    {        Charop; intN; scanf ("%c%d",&op,&N); if(op=='A')        {            inttemp = (n+t)%D; a[++cnt]=temp;        Update (CNT); }        Else{printf ("%d\n", T = query (cnt-n+1, CNT)); }    }    return 0;}

Tree-like array maintenance interval max