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显示标签为“作业”的博文。显示所有博文

2008年11月6日星期四

C++表达式计算

又是给某人写的作业... 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

using namespace std;

//栈内优先级

map isp;

//入栈优先级

map icp;

//分离表达式

list Tokenize(const string& str,const string& delimiters){

    list tokens;

    string::size_type delimPos = 0, tokenPos = 0, pos = 0;

    if(str.length()<1)  return tokens;

    while(1){

        delimPos = str.find_first_of(delimiters, pos);

        tokenPos = str.find_first_not_of(delimiters, pos);

        if(string::npos != delimPos){

            if(string::npos != tokenPos){

                if(tokenPos                    tokens.push_back(str.substr(pos,delimPos-pos));

                }else{

                    tokens.push_back("");

                }

            }else{

                tokens.push_back("");

            }

            pos = delimPos+1;

        } else {

            if(string::npos != tokenPos){

                tokens.push_back(str.substr(pos));

            } else {

                tokens.push_back("");

            }

            break;

        }

    }

    return tokens;

}

inline bool isNumber(char c){

    return c=='.'||'0'<=c&&c<='9';

}

inline bool isSymbol(string op) {

	return op=="+"||op=="-"||op=="*"||op=="/"||op=="%"||op=="^"||op=="("||op==")";

}

inline bool isSpace(char c){

    return c==' '||c=='\t'||c=='\n'||c=='\r';

}

//格式化&分离表达式

list toExpressionArray(string exp){

    string fexp;

    const char* data = exp.data();

    int idx = 0;

    int len = exp.length();

    for(;idx        char c = data[idx];

        if(isNumber(c)){

            fexp.push_back(c);

        }

        else if(!isSpace(c)){

            fexp.push_back(' ');

            fexp.push_back(c);

            fexp.push_back(' ');

        }

    }

    return Tokenize(fexp," ");

}



//中序换前序

list m2l(list m) {

	list l;

	stack s;

	string op;

	string y;

	s.push("#");

    for(list::const_iterator i = m.begin();i!=m.end();i++){

	    op = *i;

	    if(op=="")

            continue;

	    if(!isSymbol(op)){

            l.push_back(op);

	    }else{

            if(icp[op]>isp[s.top()]){

                s.push(op);

            }else if(op==")"){

                y = s.top();

                s.pop();

                while(y!="("){

                    l.push_back(y);

                    y = s.top();

                    s.pop();

                }

            }else{

                y = s.top();

                s.pop();

                while(icp[op]                    l.push_back(y);

                    y = s.top();

                    s.pop();

                }

                s.push(y);

                s.push(op);

            }//if2

	    }//if1

	}//for

	while(s.top()!="#"){

	    l.push_back(s.top());

	    s.pop();

	}

	return l;

}

//计算

double _calc(double o1, double o2, char op) {

	switch(op){

	    case '+':{

            return o1+o2;

	    }

	    case '-':{

            return o1-o2;

	    }

	    case '*':{

            return o1*o2;

	    }

	    case '/':{

            return o1/o2;

	    }

	    case '^':{

            return pow(o1,o2);

	    }

	}

	return 0;

}

//计算前序表达式

double calc(list in){

	stack sk;

	for(list::const_iterator i = in.begin();i!=in.end();i++){

	    string op = *i;

	    if(!isSymbol(op)){

            sk.push(atof(op.data()));

	    }else{

            double o2 = sk.top();

            sk.pop();

            double o1 = sk.top();

            sk.pop();

            char o = op.data()[0];

            double r = _calc(o1,o2,o);

            sk.push(r);

	    }

	}

	return sk.top();

}

//没用

void printList(list l){

    int x=0;

    for(list::const_iterator i = l.begin();i!=l.end();i++){

        cout<<++x<<":"<<*i<    }

}

int main()

{

    isp["+"]=3;

	isp["-"]=3;

	isp["*"]=5;

	isp["/"]=5;

	isp["%"]=5;

	isp["^"]=5;

	isp["("]=1;

	isp[")"]=6;

	isp["#"]=0;



	icp["+"]=2;

	icp["-"]=2;

	icp["*"]=4;

	icp["/"]=4;

	icp["%"]=4;

	icp["^"]=4;

	icp["("]=6;

	icp[")"]=1;

	icp["#"]=0;



    string exp;

    cout<<"Exp:";

    cin>>exp;

    list l1 = toExpressionArray(exp);

    printList(l1);

    list l2 = m2l(l1);

    printList(l2);

    double r = calc(l2);

    cout<<"Result:"<    return 0;

}
时间： 11/06/2008 03:47:00 下午 1 人次吐槽 标签： , , ,

2008年7月6日星期日

某人的作业，有用的拿走

今天下午五分钟给某人赶制的作业一份，有需要的拿走。
关键字：java socket tcp 文件传输


import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.Socket;
import javax.net.ServerSocketFactory;
import javax.net.SocketFactory;

/*
 * Copyrights (C) 2008 Bearice (Bearice@Gmail.com)
 * Release under GNU/GPL Version 2.
 */
/**
 *
 * @author Bearice
 */
public class FileTransport {

    public static void send(String args[]) throws Exception {
        String host = args[1];
        int port = Integer.parseInt(args[2]);
        System.out.printf("Connecting to %s:%d\n", host, port);
        Socket socket = SocketFactory.getDefault().createSocket(host, port);
        FileInputStream fis = new FileInputStream(args[3]);
        int b;
        System.out.println("Sending...");
        BufferedOutputStream bos = new BufferedOutputStream(socket.getOutputStream());
        while ((b = fis.read()) != -1) {
            bos.write(b);
        }
        bos.close();
    }

    public static void recv(String args[]) throws Exception {
        int port = Integer.parseInt(args[1]);
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(args[2]));
        System.out.printf("Listening on port %d\n", port);
        Socket socket = ServerSocketFactory.getDefault().createServerSocket(port).accept();
        int b;
        InputStream is = socket.getInputStream();
        System.out.println("Recving...");
        while ((b = is.read()) != -1) {
            bos.write(b);
        }
        bos.close();
    }

    public static void main(String[] args) throws Exception {
        if (args.length == 4 && args[0].equalsIgnoreCase("send")) {
            send(args);
        } else if (args.length == 3 && args[0].equalsIgnoreCase("recv")) {
            recv(args);
        } else {
            System.out.println("Usage:");
            System.out.println("FileTransport [recv|send <host>] <port> <file>");
        }
    }
}
时间： 7/06/2008 09:54:00 下午 2 人次吐槽 标签： , , , , , ,
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