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class Solution {
public:
    vector<int> asteroidCollision(vector<int>& asteroids)     {
        for (int i=0; i<asteroids.size(); i++){
            if (asteroids[i]<0){
                for (int j=i-1; j>-1; j--){
                    if (asteroids[j]>0){
                        if ((asteroids[i]*-1)>asteroids[j])
                            asteroids[j]=0;
                        else if ((asteroids[i]*-1)<asteroids[j]){
                            asteroids[i]=0;
                            break;
                        }
                        else{
                            asteroids[i]=0;
                            asteroids[j]=0;
                            break;
                        }
                    }
                }
            }
        }
        asteroids.erase(remove(asteroids.begin(), asteroids.end(), 0), asteroids.end()); 
        return(asteroids);
    }
};