Submission #252704

#	Time	Username	Problem	Language	Result	Execution time	Memory
252704		ChrisT	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	100 / 100	233 ms	13180 KiB

foehn_phenomena

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int MN = 2e5 + 5;
ll bit[MN], a[MN];
void update (int i, ll v) {
	for (;i<MN;i+=i&-i)
		bit[i] += v;
}
ll query (int i) {
	ll ret = 0;
	for (;i;i^=i&-i)
		ret += bit[i];
	return ret;
}
int main () { 
	int n,q,s,t; ll sum = 0;
	scanf ("%d %d %d %d",&n,&q,&s,&t);
	for (int i = 0; i <= n; i++) {
		scanf ("%lld",&a[i]);  if (!i) continue;
		update(i,a[i]); update(i+1,-a[i]);
		if (a[i] <= a[i-1]) sum += (ll)t * (a[i-1] - a[i]);
		else sum -= (ll)s * (a[i]-a[i-1]);
	}
	while (q--) {
		int l,r,x;
		scanf ("%d %d %d",&l,&r,&x);
		if (l > 0) {
			a[l] = query(l); a[l-1] = query(l-1);
			if (a[l] <= a[l-1]) sum -= (ll)t * (a[l-1] - a[l]);
			else sum += (ll)s * (a[l]-a[l-1]);
		}
		if (r < n) {
			a[r+1] = query(r+1); a[r] = query(r);
			if (a[r+1] <= a[r]) sum -= (ll)t * (a[r] - a[r+1]);
			else sum += (ll)s * (a[r+1]-a[r]);
		}
		update(l,x); update(r+1,-x);
		if (l > 0) {
			a[l] = query(l); a[l-1] = query(l-1);
			if (a[l] <= a[l-1]) sum += (ll)t * (a[l-1] - a[l]);
			else sum -= (ll)s * (a[l]-a[l-1]);
		}
		if (r < n) {
			a[r+1] = query(r+1); a[r] = query(r);
			if (a[r+1] <= a[r]) sum += (ll)t * (a[r] - a[r+1]);
			else sum -= (ll)s * (a[r+1]-a[r]);
		}
		printf ("%lld\n",sum);
	}
    return 0;
}

Compilation message (stderr)

foehn_phenomena.cpp: In function 'int main()':
foehn_phenomena.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d %d %d %d",&n,&q,&s,&t);
  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
foehn_phenomena.cpp:20:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%lld",&a[i]);  if (!i) continue;
   ~~~~~~^~~~~~~~~~~~~~
foehn_phenomena.cpp:27:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d %d %d",&l,&r,&x);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~

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