Submission #112040

#	TimeUTC-0	Username	Problem	Language	Result	Execution time	Memory
112040	2019-05-17 06:21:52	fredbr	Lun (COCI19_lun)	C++17	50 / 50	2 ms	384 KiB

lun

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#include <bits/stdc++.h>
using namespace std;
bool valid(string const& s) {
    auto f = [](int x) {
        if (x >= 10) return x/10+x%10;
        return x;
    };
    int acc = 0;
    for (int i = (int)s.size()-2; i >= 0; i--) {
        int x = s[i]-'0';
        if ((s.size()-1-i)&1) acc += f(2*x);
        else acc += x;
    }
    acc = acc*9%10;
    return acc == s.back()-'0';
}
int main() {
    int n;
    cin >> n;
    string s;
    cin >> s;
 
 
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• Subtask 1: 50 / 50