fix isSorted

docs/notes/算法 - 排序.md

@@ -95,7 +95,7 @@ public class Bubble<T extends Comparable<T>> extends Sort<T> {
         int N = nums.length;
         boolean isSorted = false;
         for (int i = N - 1; i > 0 && !isSorted; i--) {
-            hasSorted = true;
+            isSorted = true;
             for (int j = 0; j < i; j++) {
                 if (less(nums[j + 1], nums[j])) {
                     isSorted = false;