Improved tasks 620, 1012, 1309, 1392

Author: javadev

src/main/java/g0601_0700/s0620_not_boring_movies/script.sql

@@ -1,7 +1,6 @@
 # Write your MySQL query statement below
-# #Easy #Database #2022_03_21_Time_258_ms_(28.33%)_Space_0B_(100.00%)
-SELECT *
-FROM cinema
-WHERE description != 'boring'
-AND ID % 2 = 1
-ORDER BY rating desc;
+# #Easy #Database #2025_04_23_Time_259_ms_(64.69%)_Space_0.0_MB_(100.00%)
+SELECT id, movie, description, rating
+FROM Cinema
+WHERE description != 'boring' AND id % 2 != 0
+ORDER BY rating DESC;

src/main/java/g1001_1100/s1012_numbers_with_repeated_digits/Solution.java

@@ -1,6 +1,6 @@
 package g1001_1100.s1012_numbers_with_repeated_digits;
 
-// #Hard #Dynamic_Programming #Math #2022_02_25_Time_3_ms_(28.17%)_Space_41.8_MB_(7.04%)
+// #Hard #Dynamic_Programming #Math #2025_04_23_Time_2_ms_(50.64%)_Space_40.70_MB_(60.90%)
 
 import java.util.HashSet;
 

src/main/java/g1301_1400/s1309_decrypt_string_from_alphabet_to_integer_mapping/Solution.java

@@ -1,54 +1,26 @@
 package g1301_1400.s1309_decrypt_string_from_alphabet_to_integer_mapping;
 
 // #Easy #String #Programming_Skills_I_Day_9_String
-// #2022_03_15_Time_6_ms_(28.25%)_Space_42.6_MB_(29.40%)
-
-import java.util.HashMap;
-import java.util.Map;
+// #2025_04_23_Time_0_ms_(100.00%)_Space_41.42_MB_(89.95%)
 
 public class Solution {
     public String freqAlphabets(String s) {
-        Map<String, String> map = new HashMap<>();
-        map.put("1", "a");
-        map.put("2", "b");
-        map.put("3", "c");
-        map.put("4", "d");
-        map.put("5", "e");
-        map.put("6", "f");
-        map.put("7", "g");
-        map.put("8", "h");
-        map.put("9", "i");
-        map.put("10#", "j");
-        map.put("11#", "k");
-        map.put("12#", "l");
-        map.put("13#", "m");
-        map.put("14#", "n");
-        map.put("15#", "o");
-        map.put("16#", "p");
-        map.put("17#", "q");
-        map.put("18#", "r");
-        map.put("19#", "s");
-        map.put("20#", "t");
-        map.put("21#", "u");
-        map.put("22#", "v");
-        map.put("23#", "w");
-        map.put("24#", "x");
-        map.put("25#", "y");
-        map.put("26#", "z");
-        StringBuilder sb = new StringBuilder();
-        int i = 0;
-        while (i < s.length()) {
-            if ((Integer.parseInt("" + s.charAt(i)) == 1 || Integer.parseInt("" + s.charAt(i)) == 2)
-                    && i + 1 < s.length()
-                    && i + 2 < s.length()
-                    && s.charAt(i + 2) == '#') {
-                sb.append(map.get(s.substring(i, i + 3)));
-                i += 3;
+        StringBuilder builder = new StringBuilder();
+        int i = s.length() - 1;
+        while (i >= 0) {
+            if (s.charAt(i) == '#') {
+                decryptor(builder, i - 1, i - 2, s);
+                i -= 3;
             } else {
-                sb.append(map.get("" + s.charAt(i)));
-                i++;
+                char ch = (char) (s.charAt(i) - '0' + 96);
+                builder.append(ch);
+                i--;
             }
         }
-        return sb.toString();
+        return builder.reverse().toString();
+    }
+
+    private void decryptor(StringBuilder builder, int a, int b, String s) {
+        builder.append((char) (((s.charAt(b) - '0') * 10 + s.charAt(a) - '0') + 96));
     }
 }

src/main/java/g1301_1400/s1392_longest_happy_prefix/Solution.java

@@ -1,25 +1,28 @@
 package g1301_1400.s1392_longest_happy_prefix;
 
 // #Hard #String #Hash_Function #String_Matching #Rolling_Hash
-// #2022_03_17_Time_39_ms_(28.37%)_Space_42.6_MB_(94.23%)
+// #2025_04_23_Time_5_ms_(100.00%)_Space_45.92_MB_(23.63%)
 
 public class Solution {
     public String longestPrefix(String s) {
-        int times = 2;
-        long prefixHash = 0;
-        long suffixHash = 0;
-        long multiplier = 1;
-        long len = 0;
-        // use some large prime as a modulo to avoid overflow errors, e.g. 10 ^ 9 + 7.
-        long mod = 1000000007;
-        for (int i = 0; i < s.length() - 1; i++) {
-            prefixHash = (prefixHash * times + s.charAt(i)) % mod;
-            suffixHash = (multiplier * s.charAt(s.length() - i - 1) + suffixHash) % mod;
-            if (prefixHash == suffixHash) {
-                len = (long) i + 1;
+        char c[] = s.toCharArray();
+        int n = c.length;
+        int a[] = new int[n];
+        int max = 0, i = 1;
+        while (i < n) {
+            if (c[max] == c[i]) {
+                max++;
+                a[i] = max;
+                i++;
+            } else {
+                if (max > 0) {
+                    max = a[max - 1];
+                } else {
+                    a[i] = 0;
+                    i++;
+                }
             }
-            multiplier = multiplier * times % mod;
         }
-        return s.substring(0, (int) len);
+        return s.substring(0, a[n - 1]);
     }
 }