K-workers-minimum-cost

    long long totalCost(vector<int>& costs, int k, int candidates) {
        int i=0, j=costs.size()-1;
        priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>>pq;
        vector<int>vis(costs.size(), 0);
        while(i<candidates)
        {
            vis[i]=1;
            pq.push({costs[i], i});
            i++;
        }
        i--;
        while( j>=costs.size()-candidates)
        {
            if(!vis[j])
            {
                vis[j]=1;
                pq.push({costs[j], j});
                j--;
            }else break;
        }
        j++;
        long long sum=0;
        while(!pq.empty() and k--)
        {
            int val = pq.top().first;
            int ind = pq.top().second;
            pq.pop();
            // cout<<val<<" "<<ind<<endl;
            sum+=1LL*val;
            if(ind>=j){
                j--;
                if(j>=0 and !vis[j]){
                    vis[j]=1;
                    pq.push({costs[j], j});
                }
            }else if(ind<=i){
                i++;
                if(i<costs.size() and !vis[i]){
                    vis[i]=1;
                    pq.push({costs[i], i});
                }
            }
        }

        return sum;
    }