C/字符串类STR.cpp

#include <iostream>
//编译预处理命令
#include <iostream>
#include <cstring>

class STR{  //字符串类的定义
	private:
		char *s1, *s2; //私有成员数据，s1为原串，s2为删除重复字符的新串 
	public:
		STR(); //构造函数 , 用形参str所指向的字符串初始化s1
		STR(char *str); //构造函数 , 用形参str所指向的字符串初始化s1
		void set(char *str); //用形参str所指向的字符串设置原串s1 
		void delsame(); //从s1中复制没有重复的字符到s2所指向的空间
		void show(); //输出s1, s2所指向的字符数组空间的字符串的内容
		~STR(); //析构函数, 释放s1, s2动态开辟的空间
};
//字符串类的实现
  STR::STR() {
        s1 = new char[1];
        s1[0] = '\0';
        s2 = new char[1];
        s2[0] = '\0';
    }

    STR::STR(char *str) {
        s1 = new char[strlen(str) + 1];
        strcpy(s1, str);
        s2 = new char[strlen(str) + 1];
        strcpy(s2, str);
    }

  void STR:: set(char *str) {
        delete[] s1;
        s1 = new char[strlen(str) + 1];
        strcpy(s1, str);
    }

void STR::delsame() {
    int len = strlen(s1);
    if (len == 0) return;
    int k = 0;
    s2[k++] = s1[0];

    for (int i = 1; i < len; ++i) {
        bool isDuplicate = false;
        for (int j = 0; j < k; ++j) {
            if (s1[i] == s2[j]) {
                isDuplicate = true;
                break;
            }
        }
        if (!isDuplicate) {
            s2[k++] = s1[i];
        }
    }
    s2[k] = '\0';
}

 void STR:: show() {
        std::cout << "原串：s1=" << s1 << std::endl;
        std::cout << "新串：s2=" << s2 << std::endl;
    }

  STR::  ~STR() {
        delete[] s1;
        delete[] s2;
    }

//主函数测试
int main() {
    STR test;
    char str[100];
    std::cout << "输入字符串：";
    std::cout << "\n";
    std::cin.getline(str, 100);
    test.set(str);
    test.delsame();
    test.show();
    return 0;}