121. Best Time to Buy and Sell Stock [Leetcode][C++]

class Solution { public: int maxProfit(vector<int>& prices) { // Brute Force Solution Time O(N^2) & Auxiliary Space O(1) int len=prices.size(),profit=0; for(int i=0;i<len;i++){ for(int j=i+1;j<len;j++){ if(prices[j]>prices[i]){ int pro=prices[j]-prices[i]; profit=max(profit,pro); } } } return profit; } }; 

class Solution { public: int maxProfit(vector<int>& prices) { // Efficient Solution Time O(N) & Auxiliary Space O(1) int min_val=INT_MAX,profit=0,len=prices.size(); for(int i=0;i<len;i++){ min_val=min(min_val,prices[i]); profit=max(profit,prices[i]-min_val); } return profit; } };