Buy Low, Sell High

#include <iostream>
 
using namespace std;
 
int main() {
    int le, e;
    cin >> le;
 
    int l[le] = {0};
    int a[le] = {0};
 
    for (int i = 0; i < le; i++) {
        cin >> e;
        l[i] = e;
    }
 
 
    a[0] = -l[0];
    for (int i = 1; i < le; i++)
     a[i] = max(a[i-1],-l[i]);
 
    a[0] = 0;
    for (int i = 1; i < le; i++)
     a[i] = max(a[i-1], a[i] + l[i]);
 
    a[0] = -l[0];
    for (int i = 1; i < le; i++)
     a[i] = max(a[i-1], a[i] - l[i]);
 
    a[0] = 0;
    for (int i = 1; i < le; i++)
     a[i] = max(a[i-1], a[i] + l[i]);
 
    cout << a[le - 1] << endl;
 
 
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED