题目85-五键键盘(c++版)

#include <string>
#include <vector>
#include <iostream>
#include <memory>
#include <cstring>
#include <sstream>

std::string title = "有一个特殊的五键键盘\n"
                    "上面有A、Ctrl-C、Ctrl-X、Ctrl-V、Ctrl-A\n"
                    "A键在屏幕上输出一个字母A\n"
                    "Ctrl-C将当前所选的字母复制到剪贴板\n"
                    "Ctrl-X将当前选择的字母复制到剪贴板并清空所选择的字母\n"
                    "Ctrl-V将当前剪贴板的字母输出到屏幕\n"
                    "Ctrl-A选择当前屏幕中所有字母\n"
                    "注意：\n"
                    "1. 剪贴板初始为空\n"
                    "2. 新的内容复制到剪贴板会覆盖原有内容\n"
                    "3. 当屏幕中没有字母时,Ctrl-A无效\n"
                    "4. 当没有选择字母时Ctrl-C、Ctrl-X无效\n"
                    "5. 当有字母被选择时A和Ctrl-V这两个输出功能的键,\n"
                    "会先清空所选的字母再进行输出\n"
                    "\n"
                    "    给定一系列键盘输入,\n"
                    "    输出最终屏幕上字母的数量\n"
                    "\n"
                    "    输入描述:\n"
                    "输入为一行\n"
                    "为简化解析用数字12345分别代替A、Ctrl-C、Ctrl-X、Ctrl-V、Ctrl-A的输入\n"
                    "数字用空格分割\n"
                    "\n"
                    "    输出描述:\n"
                    "输出一个数字为屏幕上字母的总数量\n"
                    "\n"
                    "    示例一:\n"
                    "输入:\n"
                    "1 1 1\n"
                    "输出:\n"
                    "3\n"
                    "\n"
                    "   示例二:\n"
                    "输入:\n"
                    "1 1 5 1 5 2 4 4\n"
                    "输出:\n"
                    "2";

void Help()
{
    std::cout << title << std::endl;
    ;
}
int main(int argc, char const *argv[])
{
    if (argc > 1 && strncmp(argv[1], "-h", 2) == 0)
    {
        Help();
    }

    // get the numbers
    int n;
    std::string str;
    std::vector<int> numbers;
    std::getline(std::cin, str);
    std::stringstream sstr(str);
    while (sstr >> n)
    {
        numbers.push_back(n);
    }

    // calc screen words
    int current_words = 0, last_words = 0;     // 当前多少个字，上一次多少个字
    int current_control = 0, last_control = 0; //当前输入的控制，上一次输入的控制
    int have_words = 0;                        //剪贴板里有多少个字
    bool select_all=false;
    for (auto &n : numbers)
    {
        // std::cout << n << std::endl;
        switch (n)
        {
        case 1:
        {
            if (last_control == 5)
            {
                current_words = 1;
            }
            else
            {
                current_words++;
            }
            last_control = 1;
        }
        break;
        case 2:
        {
            if (last_control == 5)
            {
                have_words = current_words;
            }
            last_control = 2;
        }
        break;
        case 3:
        {
            if (last_control == 5)
            {
                have_words = current_words;
                current_words = 0;
            }
            last_control = 3;
        }
        break;
        case 4:
        {
            if (last_control == 5&nbs***bsp;select_all)
            {
                current_words = have_words;
                select_all=false;
            }
            else
            {
                current_words += have_words;
            }
            last_control = 4;
        }
        break;
        case 5:
        {
            last_control = 5;
            select_all=true;
        }
        break;
        default:
            break;
        }
    }

    std::cout << current_words << std::endl;
    return 0;
}