题解 | 合唱队

n = int(input())
h = list(map(int,input().split()))
def subs(s):#依次求从左往右最大同学数量
    dp = [1]*len(s)
    for i in range(len(s)):
        for j in range(i):
            if s[i]>s[j]:
                dp[i] = max(dp[i],dp[j]+1)
    return dp
l = subs(h)#合唱队左边各位同学数量
r = subs(h[::-1])[::-1]#合唱队右边各位同学数量
maxh = 0#合唱队最大同学数量
for i in range(n):#更新合唱队最大同学数量
    maxh = max(maxh,l[i]+r[i]-1)
print(n-maxh)#返回总同学数量-合唱队同学数量