fix: Various LGTM fixes

data_structures/binary_search_tree.cpp

@@ -14,17 +14,17 @@ struct node {
     node *right;
 };
 
-struct queue {
+struct Queue {
     node *t[100];
     int front;
     int rear;
 };
 
-queue q;
+Queue queue;
 
-void enqueue(node *n) { q.t[q.rear++] = n; }
+void enqueue(node *n) { queue.t[queue.rear++] = n; }
 
-node *dequeue() { return (q.t[q.front++]); }
+node *dequeue() { return (queue.t[queue.front++]); }
 
 void Insert(node *n, int x) {
     if (x < n->val) {
@@ -123,8 +123,8 @@ void Post(node *n) {
 }
 
 int main() {
-    q.front = 0;
-    q.rear = 0;
+    queue.front = 0;
+    queue.rear = 0;
     int value;
     int ch;
     node *root = new node;

math/realtime_stats.cpp

@@ -35,7 +35,7 @@ class stats_computer1 {
         n++;
         T tmp = x - K;
         Ex += tmp;
-        Ex2 += tmp * tmp;
+        Ex2 += static_cast<double>(tmp) * tmp;
     }
 
     /** return sample mean computed till last sample */

sorting/bead_sort.cpp

@@ -14,7 +14,7 @@ void beadSort(int *a, int len) {
 
     // allocating memory
     unsigned char *beads = new unsigned char[max * len];
-    memset(beads, 0, max * len);
+    memset(beads, 0, static_cast<size_t>(max) * len);
 
     // mark the beads
     for (int i = 0; i < len; i++)

sorting/comb_sort.cpp

@@ -14,7 +14,7 @@ int FindNextGap(int x) {
     return std::max(1, x);
 }
 
-void CombSort(int a[], int l, int r) {
+void CombSort(int b[], int l, int r) {
     // Init gap
     int gap = n;
 
@@ -30,8 +30,8 @@ void CombSort(int a[], int l, int r) {
 
         // Compare all elements with current gap
         for (int i = l; i <= r - gap; ++i) {
-            if (a[i] > a[i + gap]) {
-                std::swap(a[i], a[i + gap]);
+            if (b[i] > b[i + gap]) {
+                std::swap(b[i], b[i + gap]);
                 swapped = true;
             }
         }