some tasks

contests/4contest/5.cpp

@@ -0,0 +1,45 @@
+#include <list>
+#include <iostream>
+
+int main() {
+    std::list<int> l;
+
+    int n;
+    std::cin >> n;
+
+    while (n != 0) {
+        l.push_back(n);
+        std::cin >> n;
+    }
+
+    while (std::cin >> n) {
+        auto iter = l.begin();
+
+        if (n < 0) {
+            n = abs(++n);
+            if ((size_t)n >= l.size()) {
+                continue;
+            }
+
+            while (n--) ++iter;
+
+            l.erase(iter);
+        } else {
+            int tmp;
+            std::cin >> tmp;
+
+            --n;
+            while (n-- && iter != l.end()) ++iter;
+
+            l.insert(iter, tmp);
+
+            // l.insert();
+        }
+    }
+
+    for (auto& i : l) {
+        std::cout << i << std::endl;
+    }
+
+    return 0;
+}