1144 The Missing Number（JAVA）

最新推荐文章于 2021-04-09 21:38:08 发布

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最新推荐文章于 2021-04-09 21:38:08 发布

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本文介绍了一种算法，用于从给定的整数列表中找出最小的未出现的正整数。输入包括一系列整数，算法通过标记已存在的正整数来高效地找到缺失的最小正整数。

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1144 The Missing Number（20 分）

Given N integers, you are supposed to find the smallest positive integer that is NOT in the given list.
Input Specification:

Each input file contains one test case. For each case, the first line gives a positive integer N (≤105). Then N integers are given in the next line, separated by spaces. All the numbers are in the range of int.
Output Specification:

Print in a line the smallest positive integer that is missing from the input list.
Sample Input:

10
5 -25 9 6 1 3 4 2 5 17

Sample Output:

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int a;
        Boolean[] book = new Boolean[(int) (1e5+10)];
        for (int i = 0; i < 1e5+10; i++) {
            book[i] = false;
        }
        for (int i = 0; i < n; i++) {
            a = sc.nextInt();
            if(a > 0 && a <= 1e5+10) {
                book[a] = true;
            }
        }
        for (int i = 1; i <= n+5; i++) {
            if (book[i] == true) {
                continue;
            }
            else {
                System.out.println(i);
                break;
            }
        }
    }

}