class Solution{
public:
    vector<vector<int>> stockBuySell(vector<int> A, int n){
        vector<vector<int>> ans;
        
        int buy_day=0, curr_day=1 ;
        
        while(curr_day < n) {
            
            if(A[curr_day] < A[curr_day-1]) {
                
                if(buy_day != curr_day-1) 
                    ans.push_back({buy_day, curr_day-1}) ;
                
                buy_day = curr_day ;
            }
            
            curr_day++ ;
        }
        
        if(buy_day != curr_day-1)
            ans.push_back({buy_day, curr_day-1}) ;
            
        return ans ;
    }
};

 
class Solution{
public:
    vector<vector<int>> stockBuySell(vector<int> A, int n){
        
        int buy_day = 0, sell_day = 0;
        
        vector<vector<int>> res;
        
        int curr_day = 1;
        while(curr_day < n){
            
            if(A[curr_day - 1] < A[curr_day]){
                sell_day++;
            }
            else{
                if(sell_day > buy_day)
                    res.push_back({buy_day, sell_day});
                    
                buy_day = curr_day;
                sell_day = curr_day;
            }
            
            curr_day++;
        }
        
        if(buy_day != sell_day)
            res.push_back({buy_day, sell_day});
        
        return res;
    }
};

class Solution{
public:
    //Function to find the days of buying and selling stock for max profit.
   vector<vector<int>> stockBuySell(vector<int> A, int n){
       
        vector<vector<int>> ans;
        
        for(int curr_day = 0; curr_day < A.size(); curr_day++){
            
            int buy_day = curr_day;
            
            while(A[curr_day] < A[curr_day + 1] && curr_day + 1 < A.size()){
                curr_day++;
            }
            
            if(buy_day != curr_day && A[curr_day] > A[buy_day]){
                ans.push_back({buy_day, curr_day});
            }
        }
        
        return ans;
    }
};