AtCoder题解｜ABC 111B

---

题目信息 📚

【题目描述】

Kurohashi has never participated in AtCoder Beginner Contest (ABC).

The next ABC to be held is ABC $N$ (the $N$-th ABC ever held). Kurohashi wants to make his debut in some ABC $x$ such that all the digits of $x$ in base ten are the same.

What is the earliest ABC where Kurohashi can make his debut?

【输入】

The input is given from Standard Input in the following format:

$N$

【输出】

If the earliest ABC where Kurohashi can make his debut is ABC $n$, print $n$.

【数据范围】

• $100 \leq N \leq 999$
• $N$ is an integer.

【输入样例1】

111

【输出样例1】

111

The next ABC to be held is ABC $111$, where Kurohashi can make his debut.

【输入样例2】

112

【输出样例2】

222

The next ABC to be held is ABC $112$, which means Kurohashi can no longer participate in ABC $111$. Among the ABCs where Kurohashi can make his debut, the earliest one is ABC $222$.

【输入样例3】

750

【输出样例3】

777

【题目来源】

https://atcoder.jp/contests/abc124/tasks/abc124_c

---

题目解析 🍉

【题目分析】

整数版的向上取整。

(a + (b - 1)) / b * b 实现的效果和 (int)(ceil(1.0 * a / b) * b) 是一样的

【C++代码】

#include<bits/stdc++.h>

using namespace std;
typedef long long LL;

int main() {
    int n;

    cin >> n;
    cout << (int) (ceil(1.0 * n / 111) * 111) << endl;
//    cout << (n + 110) / 111 * 111 << endl;

    return 0;
}