题解 | #合唱队#

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> heights(n);
    for (int i=0; i<n; i++) {
        cin >> heights[i]; 
    }

    vector<int> left(n,1);
    vector<int> right(n,1);

    for(int i=1;i<n;i++){
        for (int j=0; j<i; j++) {
            if(heights[i] > heights[j]){
                left[i] = max(left[i], left[j] + 1);
            }
        }
    }

    for(int i = n-2; i>=0 ; i--){
        for (int j=n-1; j>i; j--) {
            if(heights[i] > heights[j]){
                right[i] = max(right[i], right[j]+1);
            }
        }
    }

    int max_len = 0;
    for(int i=0;i<n;i++){
        max_len = max(max_len, left[i]+right[i]-1);
    }

    cout << n - max_len <<endl; 

}
// 64 位输出请用 printf("%lld")