flowerbed

class Solution {
public:
    #define all(v) v.begin(), v.end()
    bool canPlaceFlowers(vector<int>& flowerbed, int n) {
        vector<int> cpy(all(flowerbed));
        int size = flowerbed.size();

        if(!n) return true;

        if(size == 1){
            if(n == 1) return flowerbed[0] == 0;
            else return false;
        }

        int valid = false;
        int cnt = 0;

        for(int i = 0; i < size; i++){
            if(!i){
                if(!flowerbed[i + 1] and !flowerbed[i]){
                    cnt++, flowerbed[i] = 1;
                }
                continue;
            }else if(i == size - 1){
                if(!flowerbed[i - 1] and !flowerbed[i]){
                    cnt++, flowerbed[i] = 1;
                }
                continue;
            }

            if(!flowerbed[i] and !flowerbed[i + 1] and !flowerbed[i - 1]){
                cnt++, flowerbed[i] = 1;
            }
        }

        valid |= (cnt >= n), cnt = 0, flowerbed = cpy;

        for(int i = 0; i < size; i++){
            if(!i){
                if(!flowerbed[size - i - 2] and !flowerbed[size - i - 1]){
                    cnt++, flowerbed[size - i - 1] = 1;
                }
                continue;
            }else if(i == size - 1){
                if(!flowerbed[size - i] and !flowerbed[size - i - 1]){
                    cnt++, flowerbed[size - i - 1] = 1;
                }
                continue;
            }

            if(!flowerbed[size - i - 1] and !flowerbed[size - i - 2] and !flowerbed[size - i]){
                cnt++, flowerbed[size - i - 1] = 1;
            }
        }

        return valid or (cnt >= n);
    }
};