与合唱队形只差输出方式，难度较低。
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
//Mystery_Sky
//
#define M 10000
#define fr(i, n) for(int i = 1; i <= n; i++)
int f_up[M], f_down[M], f[M];
int ans, n, a[M];
int main() {
scanf("%d", &n);
fr(i, n) scanf("%d", &a[i]), f_up[i] = f_down[i] = 1;
fr(i, n) {
for(int j = 1; j < i; j++)
if(a[i] > a[j]) f_up[i] = max(f_up[i], f_up[j] + 1);
}
for(int i = n; i >= 1; i--)
for(int j = n; j > i; j--)
if(a[i] > a[j]) f_down[i] = max(f_down[i], f_down[j] + 1);
fr(i, n) {
ans = max(ans, f_up[i]+f_down[i]-1);
}
printf("%d
", ans);
return 0;
}