Fzu Problem 2236 14th target (segment tree + DP)

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Fzu Problem 2236 14th target

Title Description:

Give a sequence of n numbers and ask how many of the strictly ascending sequences are in this sequence? does not require continuous

Problem Solving Ideas:

We also encountered the problem of optimizing DP with line-segment tree, and the number of programs within the expressed interval was saved in the segment tree node. First discretization sequence (in ascending order), build, and then in the order of no sort before the line to add points to the tree, each query less than the number of scenarios +1, is the current node insert can affect the number of scenarios. Add a new number to the corresponding position in the segment tree.

1#include <cstdio>2#include <queue>3#include <stack>4#include <cmath>5#include <cstring>6#include <iostream>7#include <algorithm>8 using namespacestd;9 Ten #defineLson 2*root One #defineRson 2*root+1 A typedef __int64 LL; - ConstLL mod =1000000007; - ConstLL inf= 1e14+7; the Const intMAXN =100010; -  - structnode - { +     intL, R; - LL num; +     intMid () A     { at         return(L + R)/2; -     } -} tree[maxn*4]; - LL A[MAXN], B[MAXN]; -  - voidBuild (intRootintLintR) in { -TREE[ROOT].L =l; toTREE[ROOT].R =R; +Tree[root].num =0; -     if(L = =R) the         return ; *  $ Build (Lson, L, Tree[root].mid ());Panax NotoginsengBuild (Rson, Tree[root].mid () +1, R); - } the voidInsert (intRoot, LL x,inty) + { A     if(TREE[ROOT].L = = TREE[ROOT].R && TREE[ROOT].L = =y) the     { +Tree[root].num = (tree[root].num + x)%MoD; -         return ; $     } $  -     if(Tree[root].mid () >=y) - Insert (Lson, x, y); the     Else - Insert (Rson, x, y);WuyiTree[root].num = (tree[lson].num + tree[rson].num)%MoD; the } -LL Query (intRootintLintR) Wu { -     if(TREE[ROOT].L = = L && TREE[ROOT].R = =R) About         returnTree[root].num; $  -     if(Tree[root].mid () >=R) -         returnquery (Lson, L, R); -     Else if(Tree[root].mid () <l) A         returnquery (Rson, L, R); +     Else the     { -LL num =0; $num + =query (Lson, L, Tree[root].mid ()); thenum + = query (Rson, Tree[root].mid () +1, R); the         returnNum%MoD; the     } the } -  in intMain () the { the     intN; About  the      while(SCANF ("%d", &n)! =EOF) the     { the          for(intI=0; i<n; i++) +         { -scanf ("%i64d", &a[i]); theB[i] =A[i];Bayi         } the  theSort (A, A +n); -         intm = Unique (A, a+n)-A; -  theLL ans =0; theBuild (1,0, m); the          for(intI=0; i<n; i++) the         { -LL nu, tmp = Lower_bound (A, a+m, B[i])-A; the             if(TMP = =0) theNu =0; the             Else94Nu = Query (1,0, tmp-1); the  theInsert (1, nu+1, TMP); the         }98  Aboutprintf ("%i64d\n", Query (1,0, M)); -     }101     return 0;102 }103 ///4 1 2) 2 3

Fzu Problem 2236 14th target (segment tree + DP)