Submission #289726

#	Time	Username	Problem	Language	Result	Execution time	Memory
289726		eggag32	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	30 / 100	1088 ms	14008 KiB

foehn_phenomena

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) debug(x) debug(y);
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end() 
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
const int MAXN = 2e5 + 5;
 
template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }
 
int n, q;
ll s1, t;
ll a[MAXN], s[4 * MAXN], lazy[4 * MAXN];
 
void build(int id = 1, int l = 0, int r = n){
	if((r - l) < 2){
		s[id] = a[l];
		return;
	}
	int mid = (l + r) / 2;
	build(id << 1, l, mid);
	build((id << 1) + 1, mid, r);
	s[id] = (s[id << 1] + s[(id << 1) + 1]);
}
 
void down(int id, int l, int r){
	if(lazy[id]){
		s[id] += 1LL * lazy[id] * (r - l);
		if((r - l) > 1){
			lazy[id << 1] += lazy[id];
			lazy[(id << 1) + 1] += lazy[id];
		}
	}
	lazy[id] = 0;
}
 
void increase(int x, int y, ll u, int id = 1, int l = 0, int r = n){
	//down(id, l, r);
	if(x >= r || l >= y) return;
	if(x <= l && r <= y){
		lazy[id] += u;
		down(id, l, r);
		return;
	}
	int mid = (l + r) / 2;
	increase(x, y, u, id << 1, l, mid);
	increase(x, y, u, (id << 1) + 1, mid, r);
	s[id] = (ll)(s[id << 1] + s[(id << 1) + 1]);
}
 
ll sum(int x, int y, int id = 1, int l = 0, int r = n){
	down(id, l, r);
	if(x >= r || l >= y) return 0;
	if(x <= l && r <= y) return (ll)s[id];
	int mid = (l + r) / 2;
	return (ll)(sum(x, y, id * 2, l, mid) + sum(x, y, id * 2 + 1, mid, r));
}
 
int main(){
	//freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
	scanf("%d%d%lld%lld", &n, &q, &s1, &t);
	n++;
	rep(i, n) scanf("%lld", &a[i]);
	ll cur = 0;
	repn(i, 1, n){
		if(a[i] > a[i - 1]) cur -= (a[i] - a[i - 1]) * s1;
		else cur += (a[i - 1] - a[i]) * t;
	}
	build();
	rep(i, q){
		int l, r;
		ll x;
		scanf("%d%d%lld", &l, &r, &x);
		//only need to take care of endpoints
		if(l > 0){
			//reverse the prev
			if(sum(l, l + 1) > sum(l - 1, l)) cur += (sum(l, l + 1) - sum(l - 1, l)) * s1;
			else cur -= (sum(l - 1, l) - sum(l, l + 1)) * t;
			//increase(l, l + 1, x);
			if((sum(l, l + 1)+x) > sum(l - 1, l)) cur -= ((sum(l, l + 1)+x) - sum(l - 1, l)) * s1;
			else cur += (sum(l - 1, l) - (sum(l, l + 1)+x)) * t;
			//increase(l, l + 1, -x);
		}
		if(r < (n - 1)){
			if(sum(r + 1, r + 2) > sum(r, r + 1)) cur += (sum(r + 1, r + 2) - sum(r, r + 1)) * s1;
			else cur -= (sum(r, r + 1) - sum(r + 1, r + 2)) * t;
			//increase(r, r + 1, x);
			if(sum(r + 1, r + 2) > (sum(r, r + 1)+x)) cur -= (sum(r + 1, r + 2) - (sum(r, r + 1)+x)) * s1;
			else cur += ((sum(r, r + 1)+x) - sum(r + 1, r + 2)) * t;
			//increase(r, r + 1, -x);
		}
		increase(l, r + 1, x);
		printf("%lld\n", cur);
	}
	return 0;
}
 
/*
Things to look out for:
	- Integer overflows
	- Array bounds
	- Special cases
Be careful!
*/

Compilation message (stderr)

foehn_phenomena.cpp: In function 'int main()':
foehn_phenomena.cpp:75:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   75 |  scanf("%d%d%lld%lld", &n, &q, &s1, &t);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foehn_phenomena.cpp:77:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   77 |  rep(i, n) scanf("%lld", &a[i]);
      |            ~~~~~^~~~~~~~~~~~~~~
foehn_phenomena.cpp:87:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   87 |   scanf("%d%d%lld", &l, &r, &x);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 0 / 10
• Subtask 3: 0 / 60