请求大佬帮帮本蒟蒻

#include<bits/stdc++.h>
using namespace std;
int n, a[100005];
bool check(int x) {
	int b[100005], cnt = 0;
	for (int i = 1; i <= n; i++) {
		if (a[i] > x)b[++cnt] = a[i];
	}
	for (int i = 1; i <= cnt; i += 2) {
		if (b[i] != b[i + 1])return 0;
	}
	return 1;
}
int main() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	int l = 1, r = n, mid;
	while (l <= r) {
		mid = (l + r) / 2;
		if (check(mid)) {
			l = mid+1;
		} else r = mid-1;
	}
	cout << l;
}