1882

class Solution {
typedef pair<int, int> T;
public:
    vector<int> assignTasks(vector<int>& servers, vector<int>& tasks) {
        priority_queue<T, vector<T>, greater<T>> fs;
        int n  = servers.size(), m=tasks.size();
        for(int i=0; i<n; i++)
            fs.push({servers[i], i});

        priority_queue<T, vector<T>, greater<T>> us;

        int j=0, curTime=0;
        vector<int> ans;
        while(j<m){
            curTime = max(j, curTime);
            if(fs.empty())
                curTime = us.top().first;
            while(!us.empty() && curTime>=us.top().first){
                auto ser = us.top(); us.pop();
                fs.push({servers[ser.second], ser.second});
            }
            if(!fs.empty()){
                auto ser = fs.top(); fs.pop();
                ans.push_back(ser.second);
                us.push({curTime+tasks[j], ser.second});
                j++;
            }
        }
        return ans;
    }
};