Block of interval processing

The idea of chunking is very common, which is to divide a series into k blocks and then manipulate them on the basis of blocks.

If the size of each block is magic, then the series of length n will be divided into ceil (n/magic) blocks altogether. This will have some nature:

1. The block number of the first series I is I/magic, which is the first i%magic in the block (although this one is useless).

2. If i%magic==0, stating that I is the beginning of block i/magic, the scope of section i/magic is [I/magic, (i+1)/magic).

The following is a block idea for an n-length sequence: Finds the maximum value of the sub-interval and modifies the value of a point.

1 Const intMAXN =50500;2 Const intMagic =Ten;3 intN, Q;4 intH[MAXN], B[MAXN];5 6 voidinit () {7      for(inti =0; I < n; i++) {8         if(i% Magic = =0|| H[i] > b[i/Magic]) {9B[i/magic] =H[i];Ten         } One     } A } -  - intQueryintLintr) { the     intRET =H[l]; -      for(inti = l; I <=R;) { -         if(i% Magic = =0&& i + Magic-1<=r) { -RET = max (ret, b[i/Magic]); +i + =Magic; -         } +         Else { ARET = max (ret, h[i++]); at         } -     } -     returnret; - } -  - voidUpdateintXintv) { inH[X] =v; -     intL = x/magic *Magic; to     intR = L +Magic; +      for(inti = l; I < R; i++) { -         if(i% Magic = =0|| H[i] > b[i/Magic]) { theB[i/magic] =H[i]; *         } $     }Panax Notoginseng}

Block of interval processing