1041. Be Unique (20)

最新推荐文章于 2022-11-30 08:36:14 发布

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#PAT甲级

博客介绍了火星独特的彩票规则，即第一个押注唯一数字者获胜。给出输入输出规格及示例，还进行算法分析，指出可创建数组存储打赌数字出现次数，再按打赌顺序选出首个唯一数作为胜利数，若没有则输出“None”。

Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a number chosen from [1, 104]. The first one who bets on a unique number wins. For example, if there are 7 people betting on 5 31 5 88 67 88 17, then the second one who bets on 31 wins.

Input Specification:

Each input file contains one test case. Each case contains a line which begins with a positive integer N (<=105) and then followed by N bets. The numbers are separated by a space.

Output Specification:

For each test case, print the winning number in a line. If there is no winner, print “None” instead.

Sample Input 1:

7 5 31 5 88 67 88 17

Sample Output 1:

Sample Input 2:

5 888 666 666 888 888

Sample Output 2:

None

算法分析：本题逻辑比较简单，由于打赌的数字是处于[1, 10000]之间的数，那么可以创建一个dets[10001]的数组用来存储打赌的数出现的次数。然后再根据打赌的顺序list[100000]，选出第一个出现的唯一数(unique number)作为胜利的数。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    int bets[10001] = { 0 }, list[100000] = { 0 };
    int i, n, win = -1;
    scanf("%d", &n);
    for (i = 0; i < n; i++)
    {
        scanf(" %d", &list[i]);
        bets[list[i]]++;
    }
    for (i = 0; i < n; i++)
    {
        if (bets[list[i]] == 1)
        {
            win = list[i];
            break;
        }
    }
    if (win == -1) //如果胜利数不存在
        printf("None");
    else
        printf("%d", win);

    system("pause");

    return 0;
}