123. Best Time to Buy and Sell Stock III

Q. No.-> 123. Best Time to Buy and Sell Stock III
Ans.->
class Solution {
public:
int solve(vector<int>& prices, int buy, int i,int limit,vector< vector<vector<int>>>&dp){
if( i== prices.size()){
    return 0;
}
if(limit==0){
    return 0;
}
if( dp[buy][i][limit] != -1){
    return dp[buy][i][limit];
}
  int profit=0;
    if(buy){
        int lelo= -prices[i]+ solve( prices,0,i+1,limit,dp);
        int mtlo= 0+solve( prices,1,i+1,limit,dp);
     profit= max( lelo,mtlo);
    }
    else{
        int becho=prices[i]+ solve( prices,1,i+1,limit-1,dp);
        int mtbecho= 0+solve( prices,0,i+1,limit,dp);
        profit= max( becho,mtbecho);
    }
    return dp[buy][i][limit]= profit;
}
    int maxProfit(vector<int>& prices) {
       vector< vector<vector<int>>>dp(2,vector<vector<int>>(prices.size()+1,vector<int>(3,-1)));
        return solve(prices,1,0,2,dp);
    }
};