Submission #6684285

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Source Code Expand

//#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;


int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int ans = 0;
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        int cnt = 0;
        int m = i;
        while (m) {
            cnt++;
            m /= 10;
        }
        if (cnt & 1) {
            ans++;
        }
    }
    cout << ans;
    return 0;
}

Submission Info

Judge Result