1936A - Bitwise Operation Wizard - CodeForces Solution

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

int t,n;

void solve()
{
	scanf("%d",&n);
	int realn = 0;
	for (int i = 1;i < n;i ++)
	{
		printf("? %d %d %d %d\n",realn,realn,i,i);
		fflush(stdout);
		char ch = getchar();
		while (ch != '<' && ch != '>' && ch != '=') ch = getchar();
		if (ch == '<') realn = i;
	}
	int res = realn;
	for (int i = 0;i < n;i ++)
	{
		if (i == realn) continue;
		printf("? %d %d %d %d\n",realn,res,realn,i);
		fflush(stdout);
		char ch = getchar();
		while (ch != '<' && ch != '>' && ch != '=') ch = getchar();
		if (ch == '<') res = i;
		else if (ch == '=')
		{
			printf("? %d %d %d %d\n",res,res,i,i);
			fflush(stdout);
			char ch = getchar();
			while (ch != '<' && ch != '>' && ch != '=') ch = getchar();
			if (ch == '>') res = i;
		}
	}
	printf("! %d %d\n",realn,res);
	fflush(stdout);
}

int main()
{
	scanf("%d",&t);
	while (t --) solve();
}