Set fixed container versions

To avoid redownloading every second time the pipeline runs

.drone.yml

@@ -5,16 +5,16 @@ name: default
 
 steps:
   - name: hello world
-    image: alpine
+    image: alpine:3.16.2
     commands:
       - echo hello
       - echo world
   - name: python
-    image: python
+    image: python:3.11-rc-alpine
     commands:
       - python3 -c "print(6 * 7)"
   - name: algo2
-    image: gcc
+    image: gcc:12.2.0
     commands:
       - cd algo2
       - gcc -o pairingheap pairingheap.c

algo2/pairingheap.c

@@ -166,7 +166,7 @@ int main() {
     struct PHeap ph;
     ph_init(&ph);
 
-    for (int i = 0; i < 20; i++) {
+    for (int i = 0; i < 15; i++) {
         ph_insert_malloc(&ph, rand() % 100);
     }