Submission #224930

#	Time	Username	Problem	Language	Result	Execution time	Memory
224930		NONAME	Lun (COCI19_lun)	C++17	50 / 50	5 ms	384 KiB

lun

#include <bits/stdc++.h>
#include <time.h>
//#include <random>
#define sz(x) int(x.size())
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
#define N 2 * 100500
#define oo ll(1e16)
#define pii pair <int, int>
#define pll pair <ll, ll>
#define ft first
#define sd second
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define el '\n'
#define elf endl
#define base ll(1e9 + 7)
#define re return
#define nins 4294967295
using namespace std;
typedef long long ll;
typedef long double ld;

//mt19937 rnd(0);

int n;
string s;

bool gd(string t) {
    int ans = 0;

    for (int i = sz(t) - 2; i >= 0; i -= 2) {
        int x = t[i] - '0';

        x *= 2;
        int sm = 0;
        while (x > 0) {
            sm += x % 10;
            x /= 10;
        }

        ans += sm;
        if (i + 1 != sz(t) - 1)
            ans += t[i + 1] - '0';

//        if (((ans * 9) % 10) == t[sz(t) - 1] - '0')
//            return 1;
    }

    if (sz(t) & 1)
        ans += t[0] - '0';

    if (((ans * 9) % 10) == t[sz(t) - 1] - '0')
        return 1;

    return 0;
}

void solve() {
    cin >> n;
    cin >> s;

    if (sz(s) == 1) {
        cout << 0;
        return;
    }

    int ps = -1;

    for (int i = 0; i < n; i++)
        if (s[i] == 'x')
            ps = i;

    for (char c = '0'; c <= '9'; c++) {
        s[ps] = c;

        if (gd(s)) {
            cout << c;
            return;
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifdef _LOCAL
        in("input.txt");

        int t = 1;
//        cin >> t;
        for (int i = 1; i <= t; i++) {
            cout << "Test #" << i << elf;

            clock_t start_time = clock();

            solve();

            cerr.precision(4); cerr << fixed;
            cerr << elf;
            cerr << "Time :: " << ld(clock() - start_time) / CLOCKS_PER_SEC << elf;

            cout << elf;
        }
    #else
        int t = 1;
//        cin >> t;

        while (t--) {
            solve();
            cout << el;
        }
    #endif
}

• Subtask 1: 50 / 50