Leetcode: 121(Best Time to Buy and Sell Stock)

We can use sliding window technique to solve this problem in O(n) time. The answer of the question given below:

#include<bits/stdc++.h>

using namespace std;

int main()

{

optimize();

int arr[6]= {7,6,4,3,1,8};

int n=arr[0],mx=0;

for(int i=1; i<6; i++)

{

if(arr[i]>n)

{

int x = arr[i]-n;

mx = max(mx,x);

}

else

{

n = arr[i];

}

cout<<mx<<endl;

return 0;

}

Time Complexity: O(n)

Space Complexity: O(1)

Question Link: Best Time to Buy and Sell Stock - LeetCode

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