Submission #657087

#	Time	Username	Problem	Language	Result	Execution time	Memory
657087		Juan	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	100 / 100	597 ms	14608 KiB

foehn_phenomena

#include<bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
#define ll long long

ll v[maxn], vans[maxn];
ll bit[maxn];

void upd(int id, int val){
	for(; id < maxn; id+=id&-id) bit[id] += val;
}

ll sum(int id){
	ll rt = 0;
	for(; id>0; id-=id&-id) rt += bit[id];
	return rt;
}

int main(){
	int n, q, s, t; cin >> n >> q >> s >> t;
	for(int i = 0; i <= n; i++) cin >> v[i];

	ll ans = 0;
	for(int i = 0; i < n; i++){
		if(v[i+1]>v[i]) vans[i] = -(v[i+1]-v[i])*s;
		else vans[i] = (v[i]-v[i+1])*t;
		ans += vans[i];
	}
	while(q--){
		int l, r, x; cin >> l >> r >> x;
		upd(l, x), upd(r+1, -x);
		ll a=0, b=0;
		a = v[l]+sum(l) - (v[l-1]+sum(l-1));
		if(r<n) b = v[r+1]+sum(r+1) - (v[r]+sum(r));

		if(a>0) a*=-s;
		else a*=-t;
		if(b>0) b*=-s;
		else b*=-t;
		ans -= vans[l-1] + vans[r];
		ans += a+b;
		vans[l-1] = a, vans[r] = b;
		cout << ans << "\n";
	}
}

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