second commit

FirstDemo/demo.java

@@ -0,0 +1,49 @@
+package FirstDemo;
+
+import java.util.Scanner;
+
+public class demo {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        // 输入初始进制,要转换的进制数和目标进制
+        System.out.print("请输入初始进制: ");
+        int sourceBase = scanner.nextInt();
+
+        System.out.print("请输入要转换的数字: ");
+        String sourceNumber = scanner.next();
+
+        System.out.print("请输入目标进制: ");
+        int targetBase = scanner.nextInt();
+
+
+        int decimalValue = toDecimal(sourceNumber, sourceBase);
+        String targetNumber = fromDecimal(decimalValue, targetBase);
+
+        System.out.printf("转换成" + targetBase +"进制的结果为: %s\n", targetNumber);
+
+        scanner.close();
+    }
+
+    // 将输入转换为10进制
+    public static int toDecimal(String number, int base) {
+        return Integer.parseInt(number, base);
+    }
+
+    //将转换后的10进制数转换为R进制数
+    public static String fromDecimal(int number, int base) {
+        StringBuilder sb = new StringBuilder();
+        while (number > 0) {
+            int remainder = number % base;
+            // 对于大于9的数字，用字母A-F表示
+            if (remainder >= 10) {
+                sb.append((char) ('A' + remainder - 10));
+            } else {
+                sb.append(remainder);
+            }
+            number /= base;
+        }
+        return sb.reverse().toString(); //反转字符串以得到正确的顺序
+    }
+
+}