Question

我为凯撒密码创建了一个代码，其移位为25个字符。我的代码不是对字母的前半部分进行编码，而是对后半部分进行编码。我不知道为什么请帮忙。

例如，如果我尝试编码“ abcdefghijklmnopqrstuvwxyz” ，则显示为“ abcdefghijklmmlkjihgfedcba” 。如您所见，仅字母的后半部分被编码。我应该怎么做才能使其工作并编码下半部分？

import java.util.Scanner;
public class Project1 {

    public static void main(String[] args) {        

        //creating alphabet and coded alphabet arrays
        char alphabet[] = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',' '};
        char codedAlphabet[] = {'z','y','x','w','v','u','t','s','r','q','p','o','n','m','l','k','j','i','h','g','f','e','d','c','b','a',' '};

        //prompting user for encoding or decoding, and for the message
        Scanner scan = new Scanner(System.in);
        System.out.println("Enter the message: ");
        String s = scan.nextLine();
        s.toLowerCase();
        StringBuffer message = new StringBuffer( s );

        Scanner input = new Scanner(System.in);
        System.out.println("Enter 1 to encode message, 2 to decode message: ");
        int choice = input.nextInt();
        if(choice == 1){
            encode(message, alphabet, codedAlphabet);
            System.out.println(message);
        } else if(choice == 2) {

        }

    }
    //method for encoding
    public static void encode(StringBuffer message, char a[], char b[]){
        for(int i = 0; i<message.length(); i++){
            for(int j = 0; j<a.length; j++){
                if( message.charAt(i) == a[j]){
                    message.setCharAt(i, b[j]);
                }
            }
        }
    }

}

Answer 1

您的寻找正确字符的检查是正确的。但是，当您替换字符时，必须中断该内部循环。否则，如果适合所选的加密配对，则将多次替换同一字符位置。在这种情况下，您可以将第一个字符object替换为using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Runtime.InteropServices; using System.Windows.Forms; namespace MCVE { class GroupBox : System.Windows.Forms.GroupBox { const int WM_ERASEBKGND = 0x14; const int WM_PRINTCLIENT = 0x318; protected override void WndProc(ref Message m) { switch (m.Msg) { case WM_ERASEBKGND: base.WndProc(ref m); using (var g = Graphics.FromHdc(m.WParam))//CASE 1 //using (var e = new PaintEventArgs(Graphics.FromHdc(m.WParam), ClientRectangle))//CASE 2 { var e = new PaintEventArgs(g, ClientRectangle);//CASE 1 var r = new Rectangle(2, 12, Width - 4, Height - 2); using (var b = new LinearGradientBrush(r, BackColor, SystemColors.Window, LinearGradientMode.Vertical)) { e.Graphics.FillRectangle(b, r);//Draw the gradient. } } m.Result = new IntPtr(1);//Signal that no further drawing of the background is necessary by WM_PAINT. return; case WM_PRINTCLIENT: DefWndProc(ref m);//Bypass GroupBox's internal handling so that actual painting is handled by Windows. return; } base.WndProc(ref m);//Default processing of the rest of the messages. } }; class Label : System.Windows.Forms.Label { const int WM_ERASEBKGND = 0x14; const int WM_PAINT = 0xF; [DllImport("user32.dll")] static extern IntPtr BeginPaint(IntPtr hWnd, out PAINTSTRUCT lpPaint); [DllImport("user32.dll")] static extern IntPtr EndPaint(IntPtr hWnd, ref PAINTSTRUCT lpPaint); //Ask Windows to send a message to the parent to draw it's background in the current device context. [DllImport("uxtheme.dll")] extern static int DrawThemeParentBackground(IntPtr hWnd, IntPtr hdc, ref Rectangle pRect); [StructLayout(LayoutKind.Sequential)] struct PAINTSTRUCT { public IntPtr hdc; public bool fErase; public Rectangle rcPaint; public bool fRestore; public bool fIncUpdate; [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)] public byte[] rgcReserved; }; protected override void WndProc(ref Message m) { switch (m.Msg) { case WM_ERASEBKGND: var r = ClientRectangle; DrawThemeParentBackground(Handle, m.WParam, ref r); m.Result = new IntPtr(1);//Signal that no further drawing of the background is necessary by WM_PAINT. return; case WM_PAINT: PAINTSTRUCT ps; var hdc = BeginPaint(Handle, out ps); EndPaint(Handle, ref ps);//Don't paint any text so that the gradient remains visible. m.Result = IntPtr.Zero; return; } base.WndProc(ref m);//Default processing of the rest of the messages. } }; static class Program { [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); var form = new Form() { BackColor = SystemColors.Highlight }; var groupbox = new GroupBox() { Anchor = (AnchorStyles)15, FlatStyle = FlatStyle.System, Location = new Point(10, 10), Text = "groupBox1" }; form.Controls.Add(groupbox); groupbox.Controls.Add(new Label() { FlatStyle = FlatStyle.System, Location = new Point(50, 50) }); Application.Run(form); } }; }，这是正确的，但是然后再次替换此新字符gcloud compute project-info describe（返回a），这是错误的。

Answer 2

根据您的问题代码，我认为这将是答案。

public static void encode(StringBuffer message, char a[], char b[]){
    for(int i = 0; i<message.length(); i++){
        for(int j = 0; j<a.length; j++){
            if( message.charAt(i) == a[j]){
                message.setCharAt(i, b[j]);
                break;
            }
        }
    }
}

public static void decode(StringBuffer message, char a[], char b[]){
    for(int i = 0; i<message.length(); i++){
        for(int j = 0; j<a.length; j++){
            if(  message.charAt(i) == b[j]){
                message.setCharAt(i, a[j]);
                break;
            }
        }
    }
}

as撒密码java codin gproblem

2 个答案: