用Qt编译无重复字符的最长子串长度包含界面

以下是一个用Qt编写的无重复字符的最长子串长度包含界面的示例代码：

#include <QtWidgets/QApplication>
#include <QtWidgets/QMainWindow>
#include <QtWidgets/QVBoxLayout>
#include <QtWidgets/QHBoxLayout>
#include <QtWidgets/QLabel>
#include <QtWidgets/QLineEdit>
#include <QtWidgets/QPushButton>
#include <QString>
#include <QMessageBox>

int lengthOfLongestSubstring(QString s) {
    int n = s.length();
    int ans = 0;
    int left = 0, right = 0;
    QSet<QChar> occ;
    while (right < n) {
        QChar c = s[right];
        while (occ.contains(c)) {
            occ.remove(s[left]);
            left++;
        }
        occ.insert(c);
        right++;
        ans = std::max(ans, right - left);
    }
    return ans;
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QMainWindow mainWindow;
    QWidget *centralWidget = new QWidget(&mainWindow);
    QVBoxLayout *mainLayout = new QVBoxLayout(centralWidget);

    QHBoxLayout *inputLayout = new QHBoxLayout();
    QLabel *inputLabel = new QLabel("Input String:");
    QLineEdit *inputEdit = new QLineEdit();
    inputLayout->addWidget(inputLabel);
    inputLayout->addWidget(inputEdit);

    QPushButton *calculateButton = new QPushButton("Calculate");
    QLabel *resultLabel = new QLabel("Result:");

    mainLayout->addLayout(inputLayout);
    mainLayout->addWidget(calculateButton);
    mainLayout->addWidget(resultLabel);

    QObject::connect(calculateButton, &QPushButton::clicked, [&]() {
        QString inputString = inputEdit->text();
        int result = lengthOfLongestSubstring(inputString);
        QMessageBox::information(&mainWindow, "Result", QString("The length of longest substring is %1").arg(result));
    });

    mainWindow.setCentralWidget(centralWidget);
    mainWindow.show();
    return a.exec();
}

这个示例应用程序包含一个文本框，用户可以输入要计算的字符串，然后单击“计算”按钮来计算最长的不包含重复字符的子字符串的长度。计算完成后，该程序将弹出一个消息框，显示结果。