Submission #36244

#	Time	Username	Problem	Language	Result	Execution time	Memory
36244		touristk2000	Money (IZhO17_money)	C++14	100 / 100	556 ms	17648 KiB

money

#include <bits/stdc++.h>

using namespace std;
const int MAXN = (int)1e6 + 1;
int main(){
	int n;
	scanf("%d", &n);
	vector<int> a(n);
	vector<int> cnt(MAXN);
	for (int i = 0; i < n; ++i)
	{
		scanf("%d", &a[i]);
		cnt[a[i]]++;
	}
	vector<int> pr(MAXN + 1), nxt(MAXN + 1, MAXN);
	{
		int lst = 0;
		for (int i = 1; i <= MAXN; ++i)
		{
			pr[i] = lst;
			if (cnt[i])
				nxt[lst] = i, lst = i;
		}
	}
	int ans = 0;
	for (int i = n - 1; i >= 0;)
	{
		++ans;
		int j = i;
		while (i > 0)
		{
			int p = pr[a[i]];
			if (a[i - 1] == a[i])
			{
				if (cnt[a[i]] == 1)
				{
					int l = pr[a[i]];
					int r = nxt[a[i]];
					pr[r] = l;
					nxt[l] = r;
				}
				--cnt[a[i]];
				--i;
			}
			else
			{
				if (p == a[i - 1] && (cnt[a[i]] == 1 || a[j] == a[i]))
				{
					if (cnt[a[i]] == 1)
					{
						int l = pr[a[i]];
						int r = nxt[a[i]];
						pr[r] = l;
						nxt[l] = r;
					}
					--cnt[a[i]];
					--i;
				}
				else
				{
					break;
				}
			}
		}
		if (cnt[a[i]] == 1)
		{
			int l = pr[a[i]];
			int r = nxt[a[i]];
			pr[r] = l;
			nxt[l] = r;
		}
		--cnt[a[i]];
		--i;
	}
	printf("%d\n", ans);
	return 0;
}

Compilation message (stderr)

money.cpp: In function 'int main()':
money.cpp:7:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
money.cpp:12:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
                     ^

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55