[PAT-A] 1041 Be Unique

Java

测试点4、5超时

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String[] sp = reader.readLine().split(" ");

        List<String> list1 = new ArrayList<>();
        List<String> list2 = new ArrayList<>();
        for (int i = 1; i < sp.length; i++) {
            if (list1.contains(sp[i])) {
                list2.add(sp[i]);
            } else {
                list1.add(sp[i]);
            }
        }
        list1.removeAll(list2);
        if (!list1.isEmpty()) {
            System.out.print(list1.get(0));
        } else {
            System.out.print("None");
        }
    }
}

C++

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 100010;

int n;
int bets[N], cnt[N];

int main() {
    scanf("%d", &n);
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        bets[i] = x;
        cnt[x]++;
    }

    bool flag = false;
    for (int i = 0; i < n; ++i)
        if (cnt[bets[i]] == 1) {
            printf("%d\n", bets[i]);
            flag = true;
            break;
        }

    if (!flag) printf("None\n");

    return 0;
}