这题就是排序加离散化，不应该是绿题啊？

#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 100;
int n, m, a[N], b[N], c[N], g[3 * N], j = 0, cnt, ans[3 * N];
//此处省略，以防抄袭
int main()
{
    cin >> n;
    for (int i = 1; i <= n; i ++ )
    {
        cin >> a[i];
        g[j++] = a[i];
    }
    cin >> m;
    for (int i = 1; i <= m; i ++ )
    {
        cin >> b[i];
        g[j++] = b[i];
    }
    for (int i = 1; i <= m; i ++ )
    {
        cin >> c[i];
        g[j++] = c[i];
    }
    sort (g + 1, g + 1 + j);
    cnt = unique (g + 1, g + 1 + j) - g;
    //此处省略，以防抄袭
    if(ans0 == 0) printf("1\n");
    else printf("%d\n",ans0);
    return 0;
}