Fixed idea warnings

Author: javadev

src/main/java/g0201_0300/s0208_implement_trie_prefix_tree/Trie.java

@@ -7,7 +7,7 @@
 
 @SuppressWarnings("java:S1104")
 public class Trie {
-    private TrieNode root;
+    private final TrieNode root;
     private boolean startWith;
 
     private static class TrieNode {
@@ -46,7 +46,7 @@ public boolean search(String word) {
         return search(word, root, 0);
     }
 
-    public boolean search(String word, TrieNode root, int idx) {
+    private boolean search(String word, TrieNode root, int idx) {
         if (idx == word.length()) {
             startWith = true;
             return root.isWord;

src/main/java/g0401_0500/s0432_all_oone_data_structure/AllOne.java

@@ -69,12 +69,12 @@ public void dec(String key) {
 
     /* Returns one of the keys with maximal value. */
     public String getMaxKey() {
-        return tail.pre == head ? "" : (String) tail.pre.keySet.iterator().next();
+        return tail.pre == head ? "" : tail.pre.keySet.iterator().next();
     }
 
     /* Returns one of the keys with Minimal value. */
     public String getMinKey() {
-        return head.next == tail ? "" : (String) head.next.keySet.iterator().next();
+        return head.next == tail ? "" : head.next.keySet.iterator().next();
     }
 
     // helper function to make change on given key according to offset

src/main/java/g0801_0900/s0843_guess_the_word/Solution.java

@@ -15,7 +15,7 @@
  * }
  */
 public class Solution {
-    interface Master {
+    public interface Master {
         int guess(String word);
     }
 

src/main/java/g1001_1100/s1095_find_in_mountain_array/MountainArray.java

@@ -1,6 +1,6 @@
 package g1001_1100.s1095_find_in_mountain_array;
 
-interface MountainArray {
+public interface MountainArray {
     int get(int index);
 
     int length();

src/main/java/g1101_1200/s1191_k_concatenation_maximum_sum/Solution.java

@@ -3,13 +3,13 @@
 // #Medium #Array #Dynamic_Programming #2022_03_03_Time_6_ms_(73.85%)_Space_59.8_MB_(30.38%)
 
 public class Solution {
-    private long mod = 1000000007;
+    private final long MOD = 1000000007;
 
     public int kConcatenationMaxSum(int[] arr, int k) {
         // int kadane = Kadane(arr);
         // #1 when k 1 simply calculate kadanes
         if (k == 1) {
-            return (int) (kadane(arr) % mod);
+            return (int) (kadane(arr) % MOD);
         }
         // #2 else calculate the total sum and then check if sum is -Ve or +Ve
         long totalSum = 0;
@@ -19,11 +19,11 @@ public int kConcatenationMaxSum(int[] arr, int k) {
         // #3 when negative then calculate of arr 2 times only the answer is in there only
         if (totalSum < 0) {
             // when -ve sum put a extra check here of max from 0
-            return (int) Math.max(kadaneTwo(arr) % mod, 0);
+            return (int) Math.max(kadaneTwo(arr) % MOD, 0);
         } else {
             // #4 when sum is positve then the ans is kadane of 2 + sum * (k-2);
             // these two are used sUm*(k-2) ensures that all other are also included
-            return (int) ((kadaneTwo(arr) + ((k - 2) * totalSum) + mod) % mod);
+            return (int) ((kadaneTwo(arr) + ((k - 2) * totalSum) + MOD) % MOD);
         }
     }
 

src/main/java/g1501_1600/s1584_min_cost_to_connect_all_points/Solution.java

@@ -32,12 +32,13 @@ public int minCostConnectPoints(int[][] points) {
         return cost;
     }
 
-    public void constructMST(
+    private void constructMST(
             int[] parent, int[][] points, boolean[] mst, PriorityQueue<Pair> pq, int[] dist) {
         if (!containsFalse(mst)) {
             return;
         }
         Pair newPair = pq.poll();
+        assert newPair != null;
         int pointIndex = newPair.getV();
         mst[pointIndex] = true;
         for (int i = 0; i < parent.length; i++) {

src/main/java/g2301_2400/s2400_number_of_ways_to_reach_a_position_after_exactly_k_steps/Solution.java

@@ -4,7 +4,7 @@
 // #2022_09_19_Time_1_ms_(99.66%)_Space_41.7_MB_(91.83%)
 
 public class Solution {
-    private int mod = 1000000007;
+    private final int MOD = 1000000007;
 
     public int numberOfWays(int startPos, int endPos, int k) {
         if (Math.abs(endPos - startPos) > k) {
@@ -23,9 +23,9 @@ public int numberOfWays(int startPos, int endPos, int k) {
         rev[1] = 1;
         int ans = k;
         for (int i = 2; i <= min; i++) {
-            rev[i] = (int) ((long) (mod - mod / i) * (long) rev[mod % i] % mod);
-            ans = (int) ((long) ans * (long) (k - i + 1) % mod);
-            ans = (int) ((long) ans * (long) rev[i] % mod);
+            rev[i] = (int) ((long) (MOD - MOD / i) * (long) rev[MOD % i] % MOD);
+            ans = (int) ((long) ans * (long) (k - i + 1) % MOD);
+            ans = (int) ((long) ans * (long) rev[i] % MOD);
         }
         return ans;
     }

src/main/java/g2501_2600/s2502_design_memory_allocator/Allocator.java

@@ -4,7 +4,7 @@
 // #2023_03_19_Time_9_ms_(100.00%)_Space_43_MB_(66.82%)
 
 public class Allocator {
-    Node root;
+    private final Node root;
 
     public Allocator(int n) {
         root = new Node(0, n, -1);
@@ -36,7 +36,7 @@ public int free(int mID) {
         return collapse(root, mID);
     }
 
-    public int collapse(Node cur, int id) {
+    private int collapse(Node cur, int id) {
         // base case
         if (cur == null) {
             return 0;

src/main/java/g2601_2700/s2612_minimum_reverse_operations/Solution.java

@@ -4,14 +4,13 @@
 // #2023_08_30_Time_19_ms_(100.00%)_Space_59_MB_(78.00%)
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class Solution {
     public int[] minReverseOperations(int n, int p, int[] banned, int k) {
         int[] out = new int[n];
-        for (int i = 0; i < n; i++) {
-            out[i] = -1;
-        }
+        Arrays.fill(out, -1);
         for (int node : banned) {
             out[node] = -2;
         }

src/main/java/g2801_2900/s2858_minimum_edge_reversals_so_every_node_is_reachable/Solution.java

@@ -4,6 +4,7 @@
 // #2023_12_19_Time_52_ms_(92.31%)_Space_119.5_MB_(75.38%)
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
@@ -22,9 +23,7 @@ public int[] minEdgeReversals(int n, int[][] edges) {
             nexts[v].add(new int[] {-1, u});
         }
         int[] res = new int[n];
-        for (int i = 0; i < n; i++) {
-            res[i] = -1;
-        }
+        Arrays.fill(res, -1);
         res[0] = dfs(nexts, 0, -1);
         Queue<Integer> queue = new LinkedList<>();
         queue.add(0);