[Bug](function) Fix function for cast string as date/datetime

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/literal/DateLiteral.java

@@ -183,6 +183,10 @@ static String normalize(String s) {
         }
 
         // normalize leading 0 for date and time
+        // The first part is 1-digit x: 000x-month-day
+        // The first part is 2-digit xy: 20xy-month-day / 19xy-month-day
+        // The first part is 3-digit xyz: 20xy-0z-day / 19xy-0z-day
+        // The first part is 4-digit xyzw: xyzw-month-day
         while (i < s.length() && partNumber < 6) {
             char c = s.charAt(i);
             if (Character.isDigit(c)) {
@@ -194,6 +198,20 @@ static String normalize(String s) {
                 int len = j - i;
                 if (len == 4 || len == 2) {
                     sb.append(s, i, j);
+                } else if (len == 3) {
+                    if (partNumber == 0) {
+                        String yy = s.substring(i, i + 2);
+                        int year = Integer.parseInt(yy);
+                        if (year >= 0 && year <= 69) {
+                            sb.append("20");
+                        } else if (year >= 70 && year <= 99) {
+                            sb.append("19");
+                        }
+                        sb.append(yy).append('-');
+                    } else {
+                        sb.append(s, i, i + 2).append(' ');
+                    }
+                    j = j - 1;
                 } else if (len == 1) {
                     if (partNumber == 0) {
                         sb.append("000").append(c);

regression-test/data/correctness_p0/test_cast_date_decimal.out

@@ -1,4 +1,16 @@
 -- This file is automatically generated. You should know what you did if you want to edit this
--- !sql --
+-- !sql1 --
 true
 
+-- !sql2 --
+2024-12-12
+
+-- !sql3 --
+2024-12-12
+
+-- !sql4 --
+2024-12-12
+
+-- !sql5 --
+2012-03-12
+

regression-test/suites/correctness_p0/test_cast_date_decimal.groovy

@@ -16,7 +16,23 @@
 // under the License.
 
 suite("test_cast_date_decimal") {
-    qt_sql """
+    qt_sql1 """
         select cast('2020-02-02' as date ) between cast('2020-02-02' as date ) and cast('2020-02-02' as date ) + 1.0;
     """
+
+    qt_sql2 """
+        select cast('2024-12-12' as date);
+    """
+
+    qt_sql3 """
+        select cast('2024.12.12' as date);
+    """
+
+    qt_sql4 """
+        select cast('24.12.12' as date);
+    """
+
+    qt_sql5 """
+        select cast('123.123' as date);
+    """
 }