Submission #1276278

#	Time	Username	Problem	Language	Result	Execution time	Memory
1276278		SmuggingSpun	Lun (COCI19_lun)	C++20	50 / 50	2 ms	576 KiB

lun

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	int n, p;
	cin >> n;
	vector<int>d;
	for(int i = 0; i < n; i++){
		char c;
		cin >> c;
		if(c == 'x'){
			d.push_back(-1);
			p = i;
		}
		else{
			d.push_back(c - '0');
		}
	}
	for(int i = 0; i < 10; i++){
		d[p] = i;
		vector<int>D = d;
		for(int j = n - 2; j > -1; j -= 2){
			if((D[j] <<= 1) > 9){
				D[j] -= 9;
			}			
		}
		int S = 0;
		for(int j = 0; j + 1 < n; j++){
			S += D[j];
		}
		if((S * 9) % 10 == D[n - 1]){
			return cout << i, 0;
		}
	}
}

Compilation message (stderr)

lun.cpp: In function 'int main()':
lun.cpp:7:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    7 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50