Submission #1050830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1050830		fryingduc	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	100 / 100	192 ms	39764 KiB

foehn_phenomena

#include "bits/stdc++.h"
using namespace std;

const int maxn = 2e5 + 5;
int n, q, s, t, a[maxn];

struct node {
    long long front, back;
    long long s, g;
    
    node() : front(0), back(0), s(0), g(0) {}
    node(long long f, long long b, long long s, long long g) : front(f), back(b), s(s), g(g) {}
    node operator+(const node &o) const {
        node res = *this;
        res.g += o.g;
        res.s += o.s;
        if(res.back < o.front) res.s += (o.front - res.back);
        else res.g += (res.back - o.front);
        res.back = o.back;
        
        return res;
    }
} tree[maxn * 4];
long long lazy[maxn * 4];
struct segment_tree {
    int n;
    segment_tree() {}
    segment_tree(int n) : n(n) {}
    void build(int ind, int l, int r) {
        if(l == r) {
            tree[ind] = node(a[l], a[l], 0, 0);
            return;
        }
        int mid = (l + r) / 2;
        build(ind * 2, l, mid);
        build(ind * 2 + 1, mid + 1, r);
        tree[ind] = tree[ind * 2] + tree[ind * 2 + 1];
    }
    void down(int ind, int l, int r) {
        tree[ind].front += lazy[ind];
        tree[ind].back += lazy[ind];
        if(l != r) {
            lazy[ind * 2] += lazy[ind];
            lazy[ind * 2 + 1] += lazy[ind];
        }
        lazy[ind] = 0;
    }
    void update(int ind, int l, int r, int x, int y, int val) {
        if(lazy[ind]) down(ind, l, r);
        if(l > y || r < x) return;
        if(x <= l and r <= y) {
            lazy[ind] += val;
            down(ind, l, r);
            return;
        }
        int mid = (l + r) / 2;
        update(ind * 2, l, mid, x, y, val);
        update(ind * 2 + 1, mid + 1, r, x, y, val);
        tree[ind] = tree[ind * 2] + tree[ind * 2 + 1];
    }
    node get(int ind, int l, int r, int x, int y) {
        if(lazy[ind]) down(ind, l, r);
        if(l > y || r < x) return node();
        if(x <= l and r <= y) return tree[ind];
        int mid = (l + r) / 2;
        return get(ind * 2, l, mid, x, y) + get(ind * 2 + 1, mid + 1, r, x, y);
    }
    void update(int x, int y, int val) {
        update(1, 1, n, x, y, val);
    }
    pair<long long, long long> get(int x, int y) {
        node res = get(1, 1, n, x, y);
        return {res.s, res.g};
    }
} st;
void solve() {
    cin >> n >> q >> s >> t;
    ++n;
    for(int i = 1; i <= n; ++i) {
        cin >> a[i];
    }
    st = segment_tree(n);
    st.build(1, 1, n);
    long long ans = 0;
    while(q--) {
        int l, r, x; cin >> l >> r >> x;
        ++l, ++r;
        
        st.update(l, r, x);
        pair<long long, long long> res = st.get(1, n);
        ans = 1ll * res.first * (-s) + 1ll * res.second * t;
        
        cout << ans << '\n';
    }
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    solve();
    return 0;
}

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