2013 寻找主元素

暴力解法：

• 记录数组
  • 用一个记录数组记录每个元素出现的次数，然后找出其中最多的次数与n/2作比较
• 枚举
  • 用一个双重for循环去遍历比较

代码实现：

//记录数组
#include<iostream>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int arr[100] = { 0 };
	int arr1[100] = { 0 };
	int num = 0;
	for (int i = 0; i < n; i++)
	{
		cin >> arr[i];
		arr1[arr[i]]++;
	}
	int Max = -1;
	for (int i = 0; i < 100; i++)
	{
		if (arr1[i] > Max)
		{
			Max = arr1[i];
			 num = i;
			
		}
	}
	if (Max > n / 2)
		cout << num;
	else
		cout << -1;
	
}

//枚举遍历
#include<iostream>
using namespace std;
int main()
{
	int n;
	int sum = 0;
	int num = 0;
	cin >> n;
	int arr[100] = { 0 };
	for (int i = 0; i < n; i++)
	{
		cin >> arr[i];
	}
	for (int p = 0; p < n; p++)

	{
		sum = 0;
		for (int k = 0; k < n; k++)
		{
			if (arr[p] == arr[k])
			{
				sum++;
				num = arr[p];
			}
		}
		if (sum > n / 2)
		{
			cout << num;
			return 0;
		}
	}
	cout << -1;
}