| 1 | class Solution { |
| 2 | public: |
| 3 | vector<int> asteroidCollision(vector<int>& asteroids) { |
| 4 | stack<int> s; |
| 5 | |
| 6 | for(int i=0;i<asteroids.size();i++) |
| 7 | { |
| 8 | if(s.empty() or asteroids[i]>0) |
| 9 | { |
| 10 | s.push(asteroids[i]); |
| 11 | } |
| 12 | else |
| 13 | { |
| 14 | while(true) |
| 15 | { |
| 16 | int top = s.top(); |
| 17 | |
| 18 | if(top<0) |
| 19 | { |
| 20 | s.push(asteroids[i]); |
| 21 | break; |
| 22 | } |
| 23 | else if(top==-asteroids[i]) |
| 24 | { |
| 25 | s.pop(); |
| 26 | break; |
| 27 | } |
| 28 | else if(top>(-asteroids[i])) |
| 29 | { |
| 30 | break; |
| 31 | } |
| 32 | else |
| 33 | { |
| 34 | s.pop(); |
| 35 | if(s.empty()) |
| 36 | { |
| 37 | s.push(asteroids[i]); |
| 38 | break; |
| 39 | } |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | vector<int> output(s.size(),0); |
| 46 | |
| 47 | for(int i=s.size()-1;i>=0;i--) |
| 48 | { |
| 49 | output[i]=s.top(); |
| 50 | s.pop(); |
| 51 | } |
| 52 | |
| 53 | return output; |
| 54 | |
| 55 | |
| 56 | } |
| 57 | }; |