arc174-1.cpp

#include <bits/stdc++.h>
using namespace std;
#define IOS                      \
    ios::sync_with_stdio(false); \
    cin.tie(nullptr);            \
    cout.tie(nullptr);
#define int long long
const int maxn = 3e5 + 1;
int a[maxn], dp[maxn], sum;
signed main()
{
    IOS;
    int n, c;
    cin >> n >> c;
    for (int i = 1; i <= n; i++)
        cin >> a[i], sum += a[i];
    if (c > 0)
    {
        for (int i = 1; i <= n; i++)
        {
            dp[i] = max(dp[i - 1] + a[i], a[i]);
        }
        int ans = 0;
        for (int i = 1; i <= n; i++)
        {
            ans = max(ans, dp[i]);
        }
        cout << sum - ans + ans * c << endl;
        system("pause");
        return 0;
    }
    for (int i = 1; i <= n; i++)
    {
        dp[i] = min(dp[i - 1] + a[i], a[i]);
    }
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        ans=min(ans,dp[i]);
    }
    cout<<sum-ans+ans*c<<endl;
    system("pause");
    return 0;
}