Given an array of integers representing cars in a row. The indices of the cars in the array represent their positions. For each car, the value represents its size, and the sign represents its direction (+ve -> right and -ve -> left). Each car moves at the same speed. Find out the state of the cars after all collisions. If two cars collide, the smaller one will explode. If both are the same size, both will explode. Two cars moving in the same direction will never meet.