全部问题

问题很简单：为什么线程安全字典允许数据竞争，因为该字典中的所有方法都是原子的，并且两个线程不应该接收相同的值？

在下面的示例中，可以显示至少10个、至少12个、至少14个。

public class Program
{
    private static ConcurrentDictionary<string, int> _map = [];

    static async Task Main(string[] args)
    {
        _map["air"] = 0;
        var tasks = new List<Task>();

        for (int i = 0; i < 10000; i++)
        {
            tasks.Add(Task.Run(() =>
            {
                for (int i = 0; i < 10; i++)
                {
                    _map.TryGetValue("air", out int value);
                    _map.AddOrUpdate("air", value, (key, oldValue) => oldValue + 1);

                    _map.TryGetValue("air", out int newValue);
                    if (newValue >= 10)
                    {
                        _map.TryRemove("air", out _);
                        _map.TryAdd("air1", newValue);
                    }
                }
            }));
        }

        await Task.WhenAll(tasks);
        Console.WriteLine(_map["air1"]);
    }
}

有表1

表2

我们需要一个sql查询，它将返回表1和一个附加字段，其中列中包含表2的正值和负值之间的差异isPoitiveReaction

我需要这样安排组件：在第一行中有 2 个按钮，占据窗口整个高度的一半，它们的宽度比是 1:2，在第二行中一切都相同，但宽度比是2:1。我使用 GridBagLayout 来布局组件，因为......我发现它对于我的应用程序布局来说足够简单和灵活，但它并不像我想象的那样工作。

我写了代码：

Container pane = getContentPane();
pane.setLayout(new GridBagLayout());
GridBagConstraints layout = new GridBagConstraints();

JButton openButton = new JButton(OPEN_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.33;
layout.weighty = 0.5;
layout.gridx = 0;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(openButton, layout);

JButton saveButton = new JButton(SAVE_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.66;
layout.weighty = 0.5;
layout.gridx = 1;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(saveButton, layout);

JButton reverseButton = new JButton(REVERSE_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.66;
layout.weighty = 0.5;
layout.gridx = 0;
layout.gridy = 1;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(reverseButton, layout);

JButton calculateButton = new JButton("Рассчитать");
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.33;
layout.weighty = 0.5;
layout.gridx = 1;
layout.gridy = 1;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(calculateButton, layout);

我的期望： 图1

最终输出： 图像 2

我尝试从 JPanel 创建行并在其中放置按钮，但最终输出与预期相差甚远。代码：

Container pane = getContentPane();
pane.setLayout(new GridBagLayout());
GridBagConstraints layout = new GridBagConstraints();

JPanel panel1 = new JPanel();
panel1.setBackground(Color.BLUE);
panel1.setLayout(new GridBagLayout());
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 1;
layout.weighty = 0.5;
layout.gridx = 0;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(panel1, layout);

JButton openButton = new JButton(OPEN_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.33;
layout.weighty = 1;
layout.gridx = 0;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
panel1.add(openButton, layout);

JButton saveButton = new JButton(SAVE_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.66;
layout.weighty = 1;
layout.gridx = 1;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
panel1.add(saveButton, layout);


JPanel panel2 = new JPanel();
panel2.setBackground(Color.GREEN);
panel1.setLayout(new GridBagLayout());
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 1;
layout.weighty = 0.5;
layout.gridx = 0;
layout.gridy = 1;
layout.gridwidth = 1;
layout.gridheight = 1;
pane.add(panel2, layout);

JButton reverseButton = new JButton(REVERSE_BUTTON_TEXT);
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.66;
layout.weighty = 1;
layout.gridx = 0;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
panel2.add(reverseButton, layout);

JButton calculateButton = new JButton("Рассчитать");
layout.fill = GridBagConstraints.BOTH;
layout.weightx = 0.33;
layout.weighty = 1;
layout.gridx = 1;
layout.gridy = 0;
layout.gridwidth = 1;
layout.gridheight = 1;
panel2.add(calculateButton, layout);

最终输出：图像 3

您能告诉我如何配置所需的组件排列吗？

我看到这篇文章

https://proandroiddev.com/loading-initial-data-in-launchedeffect-vs-viewmodel-f1747c20ce62

其中作者描述了数据初始化方法的优点和缺点，得出的结论是最好通过StateFlow.我决定尝试一下，前提是我使用UiState包装器作为屏幕的一般状态：

sealed class UiState<out T> {
    object Loading : UiState<Nothing>()
    data class Error(val code: Int? = null, val message: String? = null) : UiState<Nothing>()
    data class Content<T>(val data: T) : UiState<T>()
}

也就是说，我在更改之前的实现：

class MyRepo {
    fun getMyData(): Flow<List<String>> {
        return flow {
            delay(1000)
            emit(listOf("1", "2"))
        }
    }
}

class MyViewModel1(repo: MyRepo): ViewModel() {
    data class ScreenStateUI(
        val data: List<String> = emptyList(),
        val title: String = "Title"
    )

    private val _screenUiState: MutableStateFlow<UiState<ScreenStateUI>> = MutableStateFlow(UiState.Loading)
    val screenUiState: StateFlow<UiState<ScreenStateUI>> = _screenUiState.asStateFlow()

    init {
        viewModelScope.launch {
            repo.getMyData()
                .map<List<String>, UiState<ScreenStateUI>> { UiState.Content(ScreenStateUI(data = it)) }
                .collectLatest {
                    if (it is UiState.Content) {
                        _screenUiState.emit(
                            UiState.Content(data = it)
                        )
                }
        }
    }

    fun updateTitle(title: String) {
        _screenUiState.update {
            if (it is UiState.Content) {
                it.copy(data = it.data.copy(title = title))
            } else {
                it
            }
        }
    }
}

初始化期间，状态被加载，UI可以通过订阅变化screenUiState，也就是说，如果需要使用它fun updateTitle(title: String)，没有问题。

现在，我更改了实现以摆脱init块中的初始化，并在 UI 订阅事件后立即执行所有操作：

    class MyRepo {
        fun getMyData(): Flow<List<String>> {
            return flow {
                delay(1000)
                emit(listOf("1", "2"))
            }
        }
    }

class MyViewModel2(repo: MyRepo): ViewModel() {
    data class ScreenStateUI(
        val data: List<String> = emptyList(),
        val title: String = "Title"
    )

    val screenUiState: StateFlow<UiState<ScreenStateUI>> by lazy {
        repo.getMyData()
            .map<List<String>, UiState<ScreenStateUI>> { UiState.Content(ScreenStateUI(data = it)) }
            .onStart { emit(UiState.Loading) }
            .catch { emit(UiState.Error(message = it.message)) }
            .stateIn(
                scope = viewModelScope,
                started = SharingStarted.WhileSubscribed(5000),
                initialValue = UiState.Loading
            )
    }

    fun updateTitle(title: String) {
        ...
    }
}

也就是说，一切似乎都不错，实际上现在 UI 仅在订阅时才会发起请求，但现在状态无法更改，因此该方法fun updateTitle(title: String)无法更新title。

我在这里缺少什么？

问题的本质：输入是：

1. 每个输入的行数
2. 字符串（0 和 1）
3. 对字符串的操作次数（按数字替换元素）
4. 操作（格式：“数字”“字符”）

原文：https ://codeforces.com/problemset/problem/2036/C

困难在于时间限制，但是这段代码在测试2中的550代币上是错误的，我不明白问题是什么，请提示逻辑中的漏洞，提前感谢

int n = Convert.ToInt32(Console.ReadLine());
List<int> list1100 = new List<int>();
List<string> list = new List<string>();
bool result;
for (int i = 0; i < n; i++)
{
    char[] arr = Console.ReadLine().ToCharArray();
    Func(arr);
    int q = Convert.ToInt32(Console.ReadLine());
    for (int k = 0; k < q; k++)
    {
        string x = Console.ReadLine();
        if (arr.Length < 4)
        {
            list.Add("NO");
            continue;
        }

        string[] str = x.Split(' ');
        int index = Convert.ToInt32(str[0]);
        char value = Convert.ToChar(str[1]);

        result = list1100.Count > 0;
        if (value == arr[index - 1])
        {
            list.Add(result ? "YES" : "NO");
            continue;
        }

        arr[index - 1] = value;

        if (value == '1')
        {
            if (arr.Length > index + 2) // {input}100
            {
                if (arr[index] == '1' && arr[index + 1] == '0' && arr[index + 2] == '0') { if (!list1100.Contains(index - 1)) { list1100.Add(index - 1); } list.Add("YES"); continue; }
            }
            if (arr.Length >= index + 2 && index != 1) // 1{input}00
            {
                if (arr[index - 2] == '1' && arr[index] == '0' && arr[index + 1] == '0') { if (!list1100.Contains(index - 2)) { list1100.Add(index - 2); } list.Add("YES"); continue; }
            }
        }
        else // value == 0
        {
            if (arr.Length >= index + 1 && index >= 3) // 11{input}0
            {
                if (arr[index - 3] == '1' && arr[index - 2] == '1' && arr[index] == '0') { if (!list1100.Contains(index - 3)) { list1100.Add(index - 3); } list.Add("YES"); continue; }
            }
            if (arr.Length >= index && index >= 4) // 110{input}
            {
                if (arr[index - 4] == '1' && arr[index - 3] == '1' && arr[index - 2] == '0') { if (!list1100.Contains(index - 4)) { list1100.Add(index - 4); } list.Add("YES"); continue; }
            }
        }
        foreach (int ex in list1100)
        {
            if (ex <= index - 1 && index - 1 <= ex + 3)
            {
                list1100.Remove(ex);
                break;
            }
        }
        result = list1100.Count > 0;
        list.Add(result ? "YES" : "NO");
    }
}
for (int i = 0; i < list.Count; i++)
{
    Console.WriteLine(list[i]);
}

void Func(char[] arr)
{
    list1100.Clear();
    for (int j = 0; j < arr.Length - 3; j++)
    {
        if (arr[j] == '1' && arr[j + 1] == '1' && arr[j + 2] == '0' && arr[j + 3] == '0') { list1100.Add(j); }
    }
    return;
}