Rebuild code and add default filter.

burp/color/UpgradeColor.java

@@ -0,0 +1,53 @@
+package burp.color;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.List;
+
+public class UpgradeColor {
+	
+	private String endColor = "";
+	/*
+	 * 颜色升级递归算法
+	 */
+	private String colorUpgrade(List<Integer> colorList, String[] colorArray) {
+		int colorSize = colorList.size();
+		colorList.sort(Comparator.comparingInt(Integer::intValue));
+		int i = 0;
+		List<Integer> stack = new ArrayList<Integer>();
+		while (i < colorSize) {
+			if (stack.isEmpty()) {
+				stack.add(colorList.get(i));
+				i++;
+			} else {
+				if (colorList.get(i) != stack.stream().reduce((first, second) -> second).orElse(99999999)) {
+					stack.add(colorList.get(i));
+					i++;
+				} else {
+					stack.set(stack.size() - 1, stack.get(stack.size() - 1) - 1);
+					i++;
+				}
+			}
+			
+		}
+		// 利用HashSet删除重复元素
+		HashSet tmpList = new HashSet(stack);
+		if (stack.size() == tmpList.size()) {
+			stack.sort(Comparator.comparingInt(Integer::intValue));
+			if(stack.get(0).equals(-1)) {
+				this.endColor = colorArray[0];
+			} else {
+				this.endColor = colorArray[stack.get(0)];
+			}
+		} else {
+			this.colorUpgrade(stack, colorArray);
+		}
+		return "";
+	}
+	
+	public String getEndColor(List<Integer> colorList, String[] colorArray) {
+		colorUpgrade(colorList, colorArray);
+		return endColor;
+	}
+}