1807E - Interview - CodeForces Solution

#include<bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
using namespace std;
//using namespace __gnu_pbds;
//typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> indexed_set;
#define endl              '\n'
#define ff                first
#define ss                second
#define pb                emplace_back
#define ppb               pop_back
// #define int               long long
#define float             long double
#define lb                lower_bound
#define ub                upper_bound
#define sz(x)             (int)(x).size()
#define ppc               __builtin_popcountll
#define all(x)            (x).begin(), (x).end()
#define rall(x)           (x).rbegin(), (x).rend()
#define uniq(v)           (v).erase(unique(all(v)),(v).end())
#define rep(i,a,b)        for(int i=a;i<b;i++)
#define per(i,a,b)        for(int i=(a);i>=(b);i--)
#define invec(a,n)        vector<int>a(n); rep(i,0,n) cin>>a[i]
#define inarr(a,n)        int a[n]; rep(i,0,n) scanf("%d", &a[i])
#define in(k,a) for(auto k : a)
#define disp(a) in(k,a){ cout<<k<<' ';} cout<<endl
const int M=1e9+7;
#define test int t; cin>>t; while(t--)
#define SUMARR(a)   accumulate(a , a+n ,0LL)
#define SUM(v)      accumulate(all(v),0LL)
#define MAXIARR(a,n)  *max_element(a , a+n)
#define MINIARR(a,n)  *min_element(a , a+n)
#define MAX(v)      *max_element((v).begin(),(v).end())
#define MINI(v)     *min_element((v).begin(),(v).end()) 
#define PI           atan(1)*4
#define INF          INT64_MAX
#define fbo(x)       find_by_order(x)
#define ook(x)       order_of_key(x)
#define out(x)       cout<<x<<endl;
bool sortbysec(const pair<int,int> &a,const pair<int,int> &b){return (a.second < b.second);}
#define f(i,n) for(int i = 0; i < n; i++)
/////खुदी को कर बुलंद इतना के हर तकदीर से पहले खुदा बन्दे से खुद पूछे के बता तेरी रज़ा क्या है;/////
int countDivisors(int n)
{
int cnt = 0;
for (int i = 1; i <= sqrt(n); i++) {
 if (n % i == 0) {
 if (n / i == i)
  cnt++;
else // Otherwise count both
cnt = cnt + 2;
}
 }
return cnt;
}
int digitsSum(int n) {
int ans = 0;
while(n != 0) {
ans += n%10;
n /= 10;
}
return ans;
}
int binpow(int a, int b, int m){
//take INF if no Modulo
int ans = 1;
while(b>0){
if(b&1){
ans *= a;
if(ans > m) ans %= m;
}
a *= a;
if(a > m) a %= m;
b>>=1;
}
return ans;
}
int inv_mod(int b,int mod){
return binpow(b,mod-2,mod)%mod;
}
const int32_t N = 3e5 + 10;
int FLOOR(const int a, const int b) { if (a > 0 || a % b == 0) return a / b; return (a / b - 1); }
int CEIL(const int a, const int b) {return (a + b - 1) / b;}
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
int POW(int a, int b) { return b == 0 ? 1 : a * POW(a, b - 1); }
int mod_exp(int a, int b, int mod) {int res = 1; while (b > 0) {if (b & 1)res = (res * a) % mod; a = (a * a) % mod; b = b >> 1; } return res % mod; }
int mod_mul(int a, int b, int m) {a = a % m; b = b % m; return (((a * b) % m) + m) % m;}
int mod_sub(int a, int b, int m) {a = a % m; b = b % m; return (((a - b) % m) + m) % m;}
int extended_gcd(int a, int b, int &x, int &y) {if (b == 0) {x = 1; y = 0; return x; } int gcd = extended_gcd(b, a % b, y, x); y -= x * (a / b); return gcd; }
int mod_inv(int a, int b) {int r1, r2; int gcd = extended_gcd(a, b, r1, r2); assert(gcd == 1); return r1; }
int mod_div(int a, int b, int m) {a = a % m; b = b % m; return (mod_mul(a, mod_inv(b, m), m) + m) % m;}
void dosomething(){
int n;
scanf("%d", &n);
inarr(a,n);
int c[n];
c[0]=a[0];
rep(i,1,n){
c[i]=c[i-1]+a[i];
}
int l=1,r=n;
while(l<r){
    int m=l+(r-l)/2;
    printf("? %d ", m-l+1);
    rep(i,0,m-l+1){
        printf("%d ", l+i);
    }
    printf("\n");
    fflush(stdout);

    int res;
    scanf("%d", &res);
    //point =m+1
    int g=c[m-1];
    if(l>1){
        g-=c[l-2];
    }
    if(res>g){
        r=m;
    }
    else{
        l=m+1;
    }
}
printf("! %d\n", l);
fflush(stdout);
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
//cout << fixed << setprecision(9);
int t;
scanf("%d",&t);
while(t--){
dosomething();
//Case #<<t<<'='<< ;
}
    return 0;
}

// #include <cstdio>
// #include <cstring>

// using namespace std;

// int main() {
//     int l = 1, r = 1000000;
//     while (l != r) {
//         int mid = (l + r + 1) / 2;
//         printf("%d\n", mid);
//         fflush(stdout);

//         char response[3];
//         scanf("%s", response);
//         if (strcmp(response, "<") == 0)
//             r = mid - 1;
//         else
//             l = mid;
//     }

//     printf("! %d\n", l);
//     fflush(stdout);
// }