Submission #279652

#	Time	Username	Problem	Language	Result	Execution time	Memory
279652		arnold518	Exercise Deadlines (CCO20_day1problem2)	C++14	25 / 25	141 ms	14148 KiB

Main

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 2e5;

int N, A[MAXN+10];
vector<int> P[MAXN+10];

int tree[MAXN+10];
void update(int i, int k) { for(; i<=N; i+=(i&-i)) tree[i]+=k; }
int query(int i) { int ret=0; for(; i>0; i-=(i&-i)) ret+=tree[i]; return ret; }

ll ans;

int main()
{
	scanf("%d", &N);
	for(int i=1; i<=N; i++) scanf("%d", &A[i]), P[A[i]].push_back(i);

	priority_queue<int> PQ;
	for(int i=1; i<=N; i++) update(i, 1);
	for(int i=N; i>=1; i--)
	{
		for(auto it : P[i]) PQ.push(it);	
		if(PQ.empty()) return !printf("-1\n");
		int now=PQ.top(); PQ.pop();
		update(N-now+1, -1);
		ans+=query(N-now+1);
	}
	printf("%lld\n", ans);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:21:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
Main.cpp:22:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |  for(int i=1; i<=N; i++) scanf("%d", &A[i]), P[A[i]].push_back(i);
      |                          ~~~~~^~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 8 / 8