Submission #103575

#	Time	Username	Problem	Language	Result	Execution time	Memory
103575		kuko	Lun (COCI19_lun)	C++11	45 / 50	3 ms	384 KiB

lun

#include <bits/stdc++.h>

using namespace std;

char account[128];

int main()
{
	int n, d, sum = 0;
	cin >> n;
	cin >> account;
	
	int multiplier = 1;
	for( int i = n - 2; i >= 0; i -= 2 )
	{
		if( account[i] == 'x' )
		{
			multiplier = 2;
			continue;
		}
		d = account[i] - '0';
		d *= 2;
		d = d%10 + d/10;
		account[i] = d + '0';
	}
	for( int i = 0; i < n - 1; i++ )
		if( account[i] != 'x' )
			sum += account[i] - '0';
	int newsum = 0, lastdigit = account[n - 1] - '0';
	if( account[n - 1] != 'x')
	{
		for( int k = 0; k < 10; k++ )
		{
			newsum = sum + (k*multiplier)%10 + (k*multiplier)/10;
			if( (newsum * 9) % 10 == lastdigit )
			{
				cout << k;
				return 0;
			}
		}
	}
	else
	{
		srand(time(NULL));
		if( rand() % 3 == 0 )
		{
			for( int k = 0; k < 10; k++ )
				if( (sum * 9) % 10 == k )
				{
					cout << k;
					return 0;
				}
		}
	}
	return 0;
}

• Subtask 1: 45 / 50