找到以后要再扫一遍确认。

#include 
     
      #include 
      
       #define LEN 100005#define ulong unsigned long longusing namespace std;ulong A[LEN];int main(){    int n;    while (cin >> n)    {        for (int i = 0; i < n; i++)        {            cin >> A[i];        }        int count = 0;        ulong candidate = 0;        for (int i = 0; i < n; i++)        {            if (count == 0)            {                count++;                candidate = A[i];            }            else if (candidate == A[i])            {                count++;            }            else            {                count--;            }        }        count = 0;        for (int i = 0; i < n; i++)        {            if (A[i] == candidate) count++;        }        if (count * 2 > n)        {            cout << candidate << endl;        }        else        {            cout << -1 << endl;        }    }    return 0;}