[Fix](Nereids) fix leading with multi level of brace pairs (#34169)

fe/fe-core/src/main/java/org/apache/doris/nereids/hint/LeadingHint.java

@@ -51,7 +51,7 @@
 public class LeadingHint extends Hint {
     private String originalString = "";
     private final List<String> tablelist = new ArrayList<>();
-    private final List<Integer> levellist = new ArrayList<>();
+    private final List<Integer> levelList = new ArrayList<>();
 
     private final Map<RelationId, LogicalPlan> relationIdToScanMap = Maps.newLinkedHashMap();
 
@@ -101,18 +101,46 @@ public LeadingHint(String hintName, List<String> parameters, String originalStri
                 }
             } else {
                 tablelist.add(parameter);
-                levellist.add(level);
+                levelList.add(level);
             }
             lastParameter = parameter;
         }
+        normalizeLevelList();
+    }
+
+    private void removeGap(int left, int right, int gap) {
+        for (int i = left; i <= right; i++) {
+            levelList.set(i, levelList.get(i) - (gap - 1));
+        }
+    }
+
+    // when we write leading like: leading(t1 {{t2 t3} {t4 t5}} t6)
+    // levelList would like 0 2 2 3 3 0, it could be reduced to 0 1 1 2 2 0 like leading(t1 {t2 t3 {t4 t5}} t6)
+    // gap is like 0 to 2 or 3 to 0 in upper example, and this function is to remove gap when we use a lot of braces
+    private void normalizeLevelList() {
+        int leftIndex = 0;
+        // at lease two tables were needed
+        for (int i = 1; i < levelList.size(); i++) {
+            if ((levelList.get(i) - levelList.get(leftIndex)) > 1) {
+                int rightIndex = i;
+                for (int j = i; j < levelList.size(); j++) {
+                    if ((levelList.get(rightIndex) - levelList.get(j)) > 1) {
+                        removeGap(i, rightIndex, Math.min(levelList.get(i) - levelList.get(leftIndex),
+                                levelList.get(rightIndex) - levelList.get(j)));
+                    }
+                    rightIndex = j;
+                }
+            }
+            leftIndex = i;
+        }
     }
 
     public List<String> getTablelist() {
         return tablelist;
     }
 
-    public List<Integer> getLevellist() {
-        return levellist;
+    public List<Integer> getLevelList() {
+        return levelList;
     }
 
     public Map<RelationId, LogicalPlan> getRelationIdToScanMap() {
@@ -450,10 +478,10 @@ public Plan generateLeadingJoinPlan() {
         }
         logicalPlan = makeFilterPlanIfExist(getFilters(), logicalPlan);
         assert (logicalPlan != null);
-        stack.push(Pair.of(getLevellist().get(index), logicalPlan));
-        int stackTopLevel = getLevellist().get(index++);
+        stack.push(Pair.of(getLevelList().get(index), logicalPlan));
+        int stackTopLevel = getLevelList().get(index++);
         while (index < getTablelist().size()) {
-            int currentLevel = getLevellist().get(index);
+            int currentLevel = getLevelList().get(index);
             if (currentLevel == stackTopLevel) {
                 // should return error if can not found table
                 logicalPlan = getLogicalPlanByName(getTablelist().get(index++));
@@ -492,7 +520,7 @@ public Plan generateLeadingJoinPlan() {
                     logicalJoin.setBitmap(LongBitmap.or(getBitmap(newStackTop.second), getBitmap(logicalPlan)));
                     if (stackTopLevel > 0) {
                         if (index < getTablelist().size()) {
-                            if (stackTopLevel > getLevellist().get(index)) {
+                            if (stackTopLevel > getLevelList().get(index)) {
                                 stackTopLevel--;
                             }
                         } else {

regression-test/data/nereids_p0/hint/fix_leading.out

@@ -251,28 +251,30 @@ Used: leading(t1 t2 t3 )
 UnUsed:
 SyntaxError:
 
--- !select5_1 --
+-- !select6_1 --
 PhysicalResultSink
 --hashAgg[GLOBAL]
 ----PhysicalDistribute[DistributionSpecGather]
 ------hashAgg[LOCAL]
---------PhysicalProject
-----------NestedLoopJoin[LEFT_OUTER_JOIN](t3.c3 > 500)
-------------PhysicalProject
---------------PhysicalOlapScan[t3]
-------------PhysicalDistribute[DistributionSpecReplicated]
---------------PhysicalProject
-----------------NestedLoopJoin[LEFT_OUTER_JOIN](t1.c1 > 500)
-------------------PhysicalProject
---------------------filter((t1.c1 < 200))
-----------------------PhysicalOlapScan[t1]
-------------------PhysicalDistribute[DistributionSpecReplicated]
---------------------PhysicalProject
-----------------------filter((t2.c2 > 500))
-------------------------PhysicalOlapScan[t2]
+--------hashJoin[INNER_JOIN] hashCondition=((t1.c1 = t6.c6)) otherCondition=()
+----------hashJoin[INNER_JOIN] hashCondition=((t1.c1 = t2.c2) and (t1.c1 = t3.c3) and (t1.c1 = t4.c4) and (t1.c1 = t5.c5)) otherCondition=()
+------------PhysicalOlapScan[t1]
+------------PhysicalDistribute[DistributionSpecHash]
+--------------hashJoin[INNER_JOIN] hashCondition=((t2.c2 = t4.c4) and (t2.c2 = t5.c5) and (t3.c3 = t4.c4) and (t3.c3 = t5.c5)) otherCondition=()
+----------------hashJoin[INNER_JOIN] hashCondition=((t2.c2 = t3.c3)) otherCondition=()
+------------------PhysicalOlapScan[t2]
+------------------PhysicalDistribute[DistributionSpecHash]
+--------------------PhysicalOlapScan[t3]
+----------------PhysicalDistribute[DistributionSpecHash]
+------------------hashJoin[INNER_JOIN] hashCondition=((t4.c4 = t5.c5)) otherCondition=()
+--------------------PhysicalOlapScan[t4]
+--------------------PhysicalDistribute[DistributionSpecHash]
+----------------------PhysicalOlapScan[t5]
+----------PhysicalDistribute[DistributionSpecHash]
+------------PhysicalOlapScan[t6]
 
 Hint log:
-Used:
+Used: leading(t1 { { t2 t3 } { t4 t5 } } t6 )
 UnUsed:
-SyntaxError: leading(t1 t2) Msg:leading should have all tables in query block, missing tables: t3 
+SyntaxError: