Create asteroid-collision.cpp

Author: kamyu104

C++/asteroid-collision.cpp

@@ -0,0 +1,26 @@
+// Time:  O(n)
+// Space: O(n)
+
+class Solution {
+public:
+    vector<int> asteroidCollision(vector<int>& asteroids) {
+        vector<int> result;
+        for (const auto& asteroid : asteroids) {
+            bool is_exploded = false;
+            while (!result.empty() && asteroid < 0 && 0 < result.back()) {
+                if (result.back() < -asteroid) {
+                    result.pop_back();
+                    continue;
+                } else if (result.back() == -asteroid) {
+                    result.pop_back();
+                }
+                is_exploded = true;
+                break;
+            }
+            if (!is_exploded) {
+                result.emplace_back(asteroid);
+            }
+        }
+        return result;
+    }
+};