为下面的类添加复制构造函数和赋值运算符。 #include<cstring> class A{ public: A(const char *p) { len = strlen(p)+1; pchar = new char[len]; strcpy(pchar,p); } ~A() { delete pchar; pchar=0; } private: char *pchar; int len; };

下面是添加复制构造函数和赋值运算符的代码：

#include <cstring>
class A {
public:
    // 构造函数
    A(const char *p) {
        len = strlen(p) + 1;
        pchar = new char[len];
        strcpy(pchar, p);
    }
    // 复制构造函数
    A(const A& other) {
        len = other.len;
        pchar = new char[len];
        strcpy(pchar, other.pchar);
    }
    // 赋值运算符
    A& operator=(const A& other) {
        if (this != &other) {
            delete pchar;
            len = other.len;
            pchar = new char[len];
            strcpy(pchar, other.pchar);
        }
        return *this;
    }
    // 析构函数
    ~A() {
        delete pchar;
        pchar = nullptr;
    }
private:
    char *pchar;
    int len;
};

相关问题

#include <iostream> #include <cstdio> #include <cstring> using namespace std; class STRING{ char* pstr; public: STRING(const char* s="");//已实现 ~STRING();//已实现 friend istream& operator>>(istream& in, STRING& s); friend ostream& operator<<(ostream& os, const STRING& s); }; int main() { STRING s; cin >> s; cout << s << endl; return 0; } /* 请在这里填写答案，，你只需要实现输入输出运算符(>>、<<)的重载即可 */

可以这样实现输入输出运算符的重载：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

class STRING{
    char* pstr;
public:
    STRING(const char* s="");
    ~STRING();
    friend istream& operator>>(istream& in, STRING& s);        
    friend ostream& operator<<(ostream& os, const STRING& s);
};

STRING::STRING(const char* s) {
    pstr = new char[strlen(s)+1];
    strcpy(pstr, s);
}

STRING::~STRING() {
    delete []pstr;
}

istream& operator>>(istream& in, STRING& s) {
    char buffer[1024];
    in.getline(buffer, 1024);
    s.pstr = new char[strlen(buffer)+1];
    strcpy(s.pstr, buffer);
    return in;
}

ostream& operator<<(ostream& os, const STRING& s) {
    os << s.pstr;
    return os;
}

int main() {
    STRING s;
    cin >> s;
    cout << s << endl;
    return 0;
}

在输入运算符中，我们使用`getline()`函数来读取输入的字符串，然后动态分配空间并将字符串拷贝到对象的数据成员中。

在输出运算符中，我们直接输出对象的数据成员。

注意，在使用动态分配空间时，需要在析构函数中释放空间。

将下面的c语言代码转化为java代码：#include <iostream> #include <cstring> #include<cmath> #include<stdio.h> #include<map> using namespace std; //词典结构 struct S { char des[15]; //目标语言 char src[15]; //英语 }dic[100010]; //定义比较器,目标语言字典序升序排列 int cmp(const void *a, const voi

Java代码如下：

import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {

//词典结构
static class S {
String des; //目标语言
String src; //英语
}

static S[] dic = new S[100010];

//定义比较器,目标语言字典序升序排列
static class MyComparator implements Comparator<S> {
public int compare(S s1, S s2) {
return s1.des.compareTo(s2.des);
}
}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
Map<String, String> map = new HashMap<String, String>();
int cnt = 0;
while (scanner.hasNext()) {
String src = scanner.next();
String des = scanner.next();
dic[cnt] = new S();
dic[cnt].des = des;
dic[cnt].src = src;
cnt++;
}
scanner.close();

//按目标语言字典序升序排列
Arrays.sort(dic, 0, cnt, new MyComparator());

//构建映射表
for (int i = 0; i < cnt; i++) {
map.put(dic[i].des, dic[i].src);
}

//查询并输出翻译结果
while (scanner.hasNext()) {
String word = scanner.next();
if (map.containsKey(word)) {
System.out.println(map.get(word));
} else {
System.out.println("eh");
}
}
}
}