About:
hamsterdb is a database engine written in ANSI C. It supports a B+Tree index structure, uses memory mapped I/O (if available), supports cursors, and can create in-memory databases.
Release focus: Major feature enhancements
Changes:
This release comes with many changes and new features. It can manage multiple databases in one file. A new flag (HAM_LOCK_EXCLUSIVE) places an exclusive lock on the file. hamsterdb was ported to Windows CE, and the Solution file for Visual Studio 2005 now supports builds for x64. Several minor bugs were fixed, performance was improved, and small API changes occurred. Pre-built libraries for Windows (32-bit and 64-bit) are available for download.
Author:
cruppstahl
結(jié)合單片機(jī)和M a t l a b 兩者的優(yōu)點(diǎn),基于事件驅(qū)動(dòng)的中斷通信機(jī)制,提出一種Matlab 環(huán)境下PC 機(jī)與
單片機(jī)實(shí)時(shí)串行通信及數(shù)據(jù)處理的方法;完成單片機(jī)數(shù)據(jù)采集系統(tǒng)與PC 機(jī)的RS-232/RS-485 串行通
信及其通信數(shù)據(jù)的分析處理、文件存儲(chǔ)、F I R 濾波及圖形顯示;簡(jiǎn)化系統(tǒng)開(kāi)發(fā)流程,提高開(kāi)發(fā)效率。
該方法已成功應(yīng)用于一個(gè)P I C 1 6 F 8 7 6 單片機(jī)應(yīng)用系統(tǒng)實(shí)例之中
Floyd-Warshall算法描述
1)適用范圍:
a)APSP(All Pairs Shortest Paths)
b)稠密圖效果最佳
c)邊權(quán)可正可負(fù)
2)算法描述:
a)初始化:dis[u,v]=w[u,v]
b)For k:=1 to n
For i:=1 to n
For j:=1 to n
If dis[i,j]>dis[i,k]+dis[k,j] Then
Dis[I,j]:=dis[I,k]+dis[k,j]
c)算法結(jié)束:dis即為所有點(diǎn)對(duì)的最短路徑矩陣
3)算法小結(jié):此算法簡(jiǎn)單有效,由于三重循環(huán)結(jié)構(gòu)緊湊,對(duì)于稠密圖,效率要高于執(zhí)行|V|次Dijkstra算法。時(shí)間復(fù)雜度O(n^3)。
考慮下列變形:如(I,j)∈E則dis[I,j]初始為1,else初始為0,這樣的Floyd算法最后的最短路徑矩陣即成為一個(gè)判斷I,j是否有通路的矩陣。更簡(jiǎn)單的,我們可以把dis設(shè)成boolean類型,則每次可以用“dis[I,j]:=dis[I,j]or(dis[I,k]and dis[k,j])”來(lái)代替算法描述中的藍(lán)色部分,可以更直觀地得到I,j的連通情況。
給定兩個(gè)集合A、B,集合內(nèi)的任一元素x滿足1 ≤ x ≤ 109,并且每個(gè)集合的元素個(gè)數(shù)不大于105。我們希望求出A、B之間的關(guān)系。
任 務(wù)?。航o定兩個(gè)集合的描述,判斷它們滿足下列關(guān)系的哪一種:
A是B的一個(gè)真子集,輸出“A is a proper subset of B”
B是A的一個(gè)真子集,輸出“B is a proper subset of A”
A和B是同一個(gè)集合,輸出“A equals B”
A和B的交集為空,輸出“A and B are disjoint”
上述情況都不是,輸出“I m confused!”