161. Minimum Opertation to get Goal.cpp

// If 0 <= x <= 1000, then for any index i in the array (0 <= i < nums.length), you can set x
// to any of the following:
//
// x + nums[i]
// x - nums[i]
// x ^ nums[i] (bitwise-XOR)


int minimumOperations(vector<int>& nums, int start, int goal) {
        vector<bool>visited(1001,false);
        int ans=0;
        queue<int>q;
        q.push(start);

        while(!q.empty()) {
                int size=q.size();
                while(size--) {
                        int node=q.front(); q.pop();
                        if(node==goal)
                                return ans;
                        if(node>1000 || node<0 || visited[node])
                                continue;
                        visited[node]=true;

                        for(int i=0; i<nums.size(); i++) {
                                int a=node+nums[i],b=node-nums[i],c=node^nums[i];
                                for(auto j :{a,b,c})
                                        q.push(j);
                        }
                }
                ans++;
        }
        return -1;
}