4.5

program  menentukan nilai maksimal:

#include <iostream>
#include <stdio.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;
int main() { 
    int n, *arr, onee = 0, twoo, threee, total = 0, maxx = -1, temp_maxx;
    cin >> n;
    arr = new int[n];
    for (int i = 0; i < n; i++) {
        cin >> arr[i];
        total += arr[i];
    }
    // O(n^2) is the following
    for (int i = 1; i < n - 1; i++) {
        onee += arr[i - 1];
        twoo = 0;
        for (int j = i + 1; j < n; j++) {
            twoo += arr[j - 1];
            threee = total - twoo - onee;
            temp_maxx = max(max(onee, twoo), threee);
            if ((temp_maxx < maxx) || (maxx == -1))
                maxx = temp_maxx;
        }
    }
    cout << maxx;
    return 0;
}