diff --git a/BaseConverter.java b/BaseConverter.java
new file mode 100644
index 0000000..137ee16
--- /dev/null
+++ b/BaseConverter.java
@@ -0,0 +1,28 @@
+import java.util.Scanner;
+
+public class BaseConverter {
+
+    // 字符数组，用于表示大于9的数字
+    private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+
+    /**
+     * 将给定进制的字符串转换为十进制整数
+     *
+     * @param str 给定进制的字符串表示
+     * @param base 给定进制的基数
+     * @return 十进制整数
+     */
+    public static int toDecimal(String str, int base) {
+        int result = 0;
+        int power = 0;
+
+        for (int i = str.length() - 1; i >= 0; i--) {
+            char c = str.charAt(i);
+            int digit = Character.isDigit(c) ? c - '0' : c - 'A' + 10;
+            result += digit * Math.pow(base, power++);
+        }
+
+        return result;
+    }
+
+}
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