这个代码AC了
by WANG_ZHENG_MING @ 2022-08-03 10:19:46
```cpp
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>
using namespace std;
int T;
struct node
{
int x,y,id;
}a[110000],b[110000];int s[110000],ans[110000],A[110000];
bool v[110000];
bool cmp(node n1,node n2){return n1.x<n2.x;}
int main()
{
scanf("%d",&T);
while(T--)
{
int n,m=0;scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d",&a[i].x),a[i].y=i;
for(int i=1;i<=n;i++)b[i]=a[i];
sort(b+1,b+n+1,cmp);
b[1].id=1;
for(int i=2;i<=n;i++)
{
if(b[i].x!=b[i-1].x)b[i].id=b[i-1].id+1;
else b[i].id=b[i-1].id;
}
for(int i=1;i<=n;i++)a[b[i].y].id=b[i].id,m=max(m,b[i].id);
for(int i=1;i<=n;i++)ans[a[i].id]=a[i].x;memset(s,0,sizeof(s));
int maxx=0;for(int i=1;i<=n;i++)s[a[i].id]++,maxx=max(s[a[i].id],maxx);int len=0;
for(int i=1;i<=m;i++)if(s[i]==maxx)A[++len]=ans[i];
if(len==m)printf("-1\n");
else
{
printf("%d\n",len);
for(int i=1;i<len;i++)printf("%d ",A[i]);
printf("%d\n",A[len]);
}
}
return 0;
}
```
by WANG_ZHENG_MING @ 2022-08-03 10:23:00
楼上举报了
by Mr_Terminator @ 2022-08-03 10:31:09