用三分法求给定数组的最大值、最小值、数组的和的CPP代码

以下是用三分法求给定数组的最大值、最小值、数组的和的CPP代码：

#include <iostream>
#include <algorithm>
using namespace std;

const int MAXN = 100005;
int n, a[MAXN];

int main() {
    cin >> n;
    for (int i = ; i < n; i++) {
        cin >> a[i];
    }

    int l = , r = n - 1;
    while (l < r) {
        int mid1 = l + (r - l) / 3;
        int mid2 = r - (r - l) / 3;
        int sum1 = , sum2 = ;
        for (int i = l; i <= mid1; i++) {
            sum1 += a[i];
        }
        for (int i = mid2; i <= r; i++) {
            sum2 += a[i];
        }
        if (sum1 < sum2) {
            l = mid1 + 1;
        } else {
            r = mid2 - 1;
        }
    }

    int max_val = a[l], min_val = a[l], sum = ;
    for (int i = ; i < n; i++) {
        max_val = max(max_val, a[i]);
        min_val = min(min_val, a[i]);
        sum += a[i];
    }

    cout << "最大值：" << max_val << endl;
    cout << "最小值：" << min_val << endl;
    cout << "数组的和：" << sum << endl;

    return ;
}