Submission #1990

#	Time	Username	Problem	Language	Result	Execution time	Memory
1990		mh5664	지우개 (GA4_eraser)	C++98	100 / 100	25 ms	4012 KiB

eraser

#include <stdio.h>
#include <algorithm>

using namespace std;

const int MAXN = 100000;
const long long int mod = 1000000007;

long long int data[MAXN + 1];
long long int data2[MAXN + 1];
long long int sum[MAXN + 1];
long long int sum2[MAXN + 1];
int main ()
{
	int n;

	scanf ("%d", &n);
	
	for (int i = 0; i < n; ++i)
	{
		scanf ("%lld", &data[i]);
	}

	sort (data, data + n);

	sum[0] = data[0];

	for (int i = 1; i < n; ++i)
	{
		sum[i] = (sum[i - 1] + data[i]) % mod;
		if (sum[i] < 0)
			sum[i] += mod;
	}
	for (int i = 0; i < n - 1; ++i)
	{
		if (data[i] == data[i + 1])
			continue;
		else
		{
			long long int r;
			int s;
			r = ((sum[n - 1] - sum[i]) * data[i]) % mod;
			if (r < 0)
				r += mod;
			s = i;
			while (s >= 0)
			{
				if (data[s] != data[i])
					break;
				data2[s] = r;
				--s;
			}
		}
	}

	sum2[0] = data2[0];
	for (int i = 1; i < n - 1; ++i)
	{
		sum2[i] = (sum2[i - 1] + data2[i]) % mod;
		if (sum2[i] < 0)
			sum2[i] += mod;
	}

	long long int sol = 0;
	for (int i = 0; i < n - 2; ++i)
	{
		if (data[i] == data[i + 1])
			continue;
		else
		{
			long long int r;
			int s;
			r = ((sum2[n - 2] - sum2[i]) * data[i]) % mod;
			if (r < 0)
				r += mod;
			s = i;
			while (s >= 0)
			{
				if (data[s] != data[i])
					break;
				sol = (sol + r) % mod;
				if (sol < 0)
					sol += mod;
				--s;
			}
		}
	}

	printf ("%lld", sol);
	return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 16 / 16
• Subtask 4: 17 / 17
• Subtask 5: 26 / 26
• Subtask 6: 28 / 28