rt 附上代码大佬可以看看哪里错了吗

题目

#include <bits/stdc++.h>
#define int long long
#define endl '\n'
using namespace std;
int n;
int a[200005];
int sum[200005];
bool  check(int l, int r) {
	int g = sum[r] - sum[l - 1];
	cout << "?" << " " << r - l + 1 << " " << endl;
	fflush(stdout);
	for (int i = l; i <= r; i++) {
		cout << i << " ";
	}
	cout << endl;
	fflush(stdout);
	int x;
	cin >> x;
	if (g != x) {
		return 1;
	} else  	return 0 ;
}
void solve() {
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	for (int i = 1; i <= n; i++) {
		sum[i] = sum[i - 1] + a[i];
	}
	int l = 1;
	int r = n;
	while (l <= r) {
		int mid = l + r >> 1;
		if (check(l, mid)) {
			if (mid - l + 1 == 1) {
				cout << "!" << " " << l << endl;
				fflush(stdout);
				return ;
			} else if (mid - l + 1 == 2) {
				cout << "? " << 1 << " " << l << endl;
				fflush(stdout);
				int hs;
				cin >> hs;
				if (hs == a[l]) {
					cout << "!" << " " << mid << endl;
					fflush(stdout);
				} else {
					cout << "! " << l << endl;
					fflush(stdout);
				}
				return ;
			}
		else 	r = mid - 1;
		} else l = mid + 1;
	}
}
signed main() {
	int t;
	ios::sync_with_stdio();
	cin.tie(0);
	cout.tie(0);
	cin >> t;
	while (t--)solve();
	return 0;


}