Submission #329142

#	Time	Username	Problem	Language	Result	Execution time	Memory
329142		M_W	Mountains (NOI20_mountains)	C++14	64 / 100	2095 ms	10064 KiB

Mountains

#include <bits/stdc++.h>
using namespace std;
long long h[300300];
vector<long long> v;

int main(){
	int N;
	vector<long long> cnt;
	scanf("%d", &N);
	for(int i = 0; i < N; i++){
		scanf("%lld", &h[i]);
		if(i == 0){
			v.push_back(h[i]);
			cnt.push_back(0);
			continue;
		}
		auto it = upper_bound(v.begin(), v.end(), h[i]);
		v.insert(it, h[i]);
		cnt.push_back(lower_bound(v.begin(), v.end(), h[i]) - v.begin());
	}
	v.clear();
	long long sum = 0;
	for(int i = N - 1; i >= 0; i--){
		if(i == 0){
			v.push_back(h[i]);
			cnt.push_back(0);
			continue;
		}
		auto it = upper_bound(v.begin(), v.end(), h[i]);
		v.insert(it, h[i]);
		sum += cnt[i] * 1ll * (lower_bound(v.begin(), v.end(), h[i]) - v.begin()) * 1ll;
	}
	printf("%lld", sum);
}

Compilation message (stderr)

Mountains.cpp: In function 'int main()':
Mountains.cpp:9:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
Mountains.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |   scanf("%lld", &h[i]);
      |   ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 2
• Subtask 2: 0 / 4
• Subtask 3: 0 / 9
• Subtask 4: 36 / 36
• Subtask 5: 28 / 28
• Subtask 6: 0 / 9
• Subtask 7: 0 / 12