Submission #848495

#	Time	Username	Problem	Language	Result	Execution time	Memory
848495		n3rm1n	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	100 / 100	92 ms	13136 KiB

foehn_phenomena

#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
const long long MAXN = 2e5 + 10;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
long long n, q, s, t;
long long a[MAXN];
void read_array()
{
    cin >> n >> q >> s >> t;
    for (long long i = 0; i <= n; ++ i)
        cin >> a[i];
}
long long p[MAXN];
long long ans = 0;
void precompute()
{
    for (long long i = 1; i <= n; ++ i)
    {
        p[i] = a[i] - a[i-1];
        if(p[i] > 0)ans -= s * abs(p[i]);
        else ans += t * abs(p[i]);
    }
}
void solve()
{
    long long left, right, x;
    while(q --)
    {
        cin >> left >> right >> x;
        if(p[left] > 0)ans += s * abs(p[left]);
        else ans -= t * abs(p[left]);
        p[left] += x;
        if(p[left] > 0)ans -= s * abs(p[left]);
        else ans += t * abs(p[left]);
        if(right != n)
        {
            if(p[right+1] > 0)ans += s * abs(p[right+1]);
        else ans -= t * abs(p[right+1]);
        p[right+1] -= x;
        if(p[right+1] > 0)ans -= s * abs(p[right + 1]);
        else ans += t * abs(p[right + 1]);
        }
        cout << ans << endl;
    }
}
int main()
{
    speed();
    read_array();
    precompute();
    solve();
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 10 / 10
• Subtask 3: 60 / 60