嗨,我正在研究一个小野牛,以了解它是如何工作的.野牛应该解析一个句子.句子由表达式组成,表达式由单词组成.
以下是我的代码:
%{
#include <stdio.h>
#include <string.h>
void yyerror(const char *str)
{
fprintf(stderr,"error: %s\n",str);
}
int yywrap()
{
return 1;
}
main()
{
yyparse();
}
%}
%token ASSIGN RANGE OR AND WHITESPACE QUOTE LPAREN RPAREN NOT GREATER LESS
%union
{
int number;
char *string;
}
%token <number> VALUE
%token <string> WORD
%type <string> term
%type <string> expression
%%
query: /* empty */
| query expression
{
printf("WOrd:%s",$2);
}
;
expression:
term
|expression term
|expression AND term
{
printf("AND");
}
; …Run Code Online (Sandbox Code Playgroud) 我从这里下载了Code :: Blocks:http://www.codeblocks.org/downloads/26
我正在学习c编程.当我运行以下程序时,我收到错误:
iostream: No such file or directory
error: syntax error before "namespace"
warning: type defaults to `int' in declaration of `std'
warning: data definition has no type or storage class
In function `main':
error: `cout' undeclared (first use in this function)
error: (Each undeclared identifier is reported only once
error: for each function it appears in.)
error: `cin' undeclared (first use in this function)
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我正在运行以下程序:
#include <iostream>
using namespace std;
int main()
{
int …Run Code Online (Sandbox Code Playgroud) 在Set Covering问题中,我们给出了一个宇宙U,例如| U | = n,并且设置S1,......,Sk是U的子集.集合封面是来自S1的一些集合的集合C,... ......,Sk的联盟是整个宇宙U.
我正在尝试提出一种算法,该算法将找到最小数量的集合覆盖,以便我可以证明集合覆盖的贪婪算法有时会找到更多集合.
以下是我提出的:
重复每一组.1.覆盖<-Seti(i = 1 ,,, n)2.如果一个集合不是任何其他集合的子集,则将该集合置于封面.
但它在某些情况下不起作用.请帮我弄清楚找到最小集合覆盖率的算法.
我仍有问题在网上找到这个算法.有人有什么建议吗?
我有以下代码通过套接字传输文件.如何发送文件名?
Socket socket = new Socket("localhost", port);//machine name, port number
File file = new File(fileName);
// Get the size of the file
long length = file.length();
if (length > Integer.MAX_VALUE)
{
System.out.println("File is too large.");
}
byte[] bytes = new byte[(int) length];
FileInputStream fis = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(fis);
BufferedOutputStream out = new BufferedOutputStream(socket.getOutputStream());
int count;
while ((count = bis.read(bytes)) > 0)
{
out.write(bytes, 0, count);
}
out.flush();
out.close();
fis.close();
bis.close();
socket.close();
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