Implementation of differential fractional groups

The function of the difference fractional group is to modify the interval, query the point

The time complexity of the modified interval is O (1), and the time complexity of the query point is O (n)

We have to choose the method flexibly according to the data range, not to be stuck in the difference score Group

void Update (int x,int y,int  z) {    b[x]+ =Z;    B[y+1]-=z;}

The above is to modify the interval operation, x position plus the amount of modification, y+1 position minus the amount of modification, so that the entire interval element is equivalent to modify the

int sum (int  x) {    int ans=0;      for (int i=1; i<=x;i++)        ans+ =b[i]    ; return ans;}

It was convenient, but I need to add it all at the time of the inquiry.

And when it comes to preprocessing.

    b[1]=a[1];      for (int i=2; i<=n;i++)        b[i]=a[i]-a[i-1];

The following is a complete implementation code:

1 //aininot2602 //modify interval, query point3#include <iostream>4#include <cstring>5 using namespacestd;6 Const intmaxn=100005;7 Const intmaxq=100005;8 intA[MAXN];9 intB[MAXN];Ten intn,q; One voidUpdateintXintYintz) A { -b[x]+=Z; -b[y+1]-=Z; the } - intSumintx) - { -     intans=0; +      for(intI=1; i<=x;i++) -ans+=B[i]; +     returnans; A } at intMain () - { -Cin>>N; -      for(intI=1; i<=n;i++) -Cin>>A[i]; -b[1]=a[1]; in      for(intI=2; i<=n;i++) -b[i]=a[i]-a[i-1]; toCin>>Q; +      while(q--) -     { the         intx; *Cin>>x; $         if(x==1)Panax Notoginseng         { -             inty,z,w; theCin>>y>>z>>W; + Update (Y,Z,W); A         } the         if(x==2) +         { -             inty; $Cin>>y; $Cout<<sum (y) <<Endl; -         } -     } the     return 0; -}

Implementation of differential fractional groups