Submission #100295

#	Time	Username	Problem	Language	Result	Execution time	Memory
100295		mraron	Lun (COCI19_lun)	C++14	50 / 50	3 ms	384 KiB

lun

#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<cassert>
#include<cassert>
#include<unordered_map>
#include<unordered_set>
#include<functional>
#include<queue>
#include<stack>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<sstream>
#include<iomanip>
#include<cstdio>
#include<cstdlib>
#include<numeric>
using namespace std;

#define all(x) (x).begin(), (x).end()
#define pb push_back
#define xx first
#define yy second
#define sz(x) (int)(x).size()
#define gc getchar
#define IO ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define mp make_pair

#ifndef ONLINE_JUDGE
#  define LOG(x) (cerr << #x << " = " << (x) << endl)
#else
#  define LOG(x) ((void)0)
#endif

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

const double PI=3.1415926535897932384626433832795;
const ll INF = 1LL<<62;
const ll MINF = -1LL<<62;

template<typename T> T getint() {
	T val=0;
	char c;
	
	bool neg=false;
	while((c=gc()) && !(c>='0' && c<='9')) {
		neg|=c=='-';
	}

	do {
		val=(val*10)+c-'0';
	} while((c=gc()) && (c>='0' && c<='9'));

	return val*(neg?-1:1);
}

bool valid(string& t) {
	ll dsum=0;
	for(int i=sz(t)-2;i>=0;i-=2) {
		ll dupla=(t[i]-'0')*2;
		if(dupla<=9) dsum+=dupla;
		else dsum+=dupla%10+dupla/10;
	}
	//cerr<<dsum<<"\n";
	ll sum=dsum;
	for(int i=sz(t)-3;i>=0;i-=2) {
		sum+=t[i]-'0';
	}
//cerr<<t<<" "<<sum<<"\n";
	return (sum*9)%10==(t.back()-'0');
}

int main() {
	IO;
	int n;
	cin>>n;
	
	string t;
	cin>>t;
	
	auto it=find(all(t), 'x');
	int ind=it-t.begin();
	
	for(int i=0;i<=9;++i) {
		t[ind]=i+'0';
		if(valid(t)) {
			cout<<i<<"\n";
			return 0;
		}
	}
	assert(0);
	
	

	return 0;
}

• Subtask 1: 50 / 50