Acwing-116 pilot brother

The essence of this problem is the same as that of eight digits

First define a state

struct st{
     int map[4];// Handle status 
     int num;// They count 
     vector<int> s;// route 
     int a;// ID code 
}

About the steps

#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#define x first
#define y second
using namespace std;

// Defining structure 
struct st {

};



st bfs() {

	// initialization 
	queue<st> que;
	que.push();

	while () {

		st t = que.front();

		for()
			for () {

				// Make new elements 

				if()// End the process when the conditions are met ;
					return

			}

		que.pop()// Delete the head element 
	}


}




int main() {

	// receive data 
	for (.....) cin >> ...//

	// Make the header element 

	bfs();// Output results 

}

The actual code

#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#define x first
#define y second
using namespace std;

const int N = 5;

int n = 4;

bool jud[1000000];

typedef pair<int, int> two;

struct st {
	int map[N][N];
	int num;
	int a;
	vector<two> s;
}st1;

void clone(int a[][N], int b[][N]) {

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++)
			a[i][j] = b[i][j];
	}

}

void change(int x, int y, int mid[][N]) {

	for (int i = 1; i <= n; i++)
		mid[i][y] = mid[i][y] ^ 1;
	for (int i = 1; i <= n; i++)
		mid[x][i] = mid[x][i] ^ 1;
	mid[x][y] = mid[x][y] ^ 1;
}

int make(int a[][N]) {

	int sum = 0, fur = 0;

	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++)
			if (a[i][j]) sum += 1 << fur++;
			else fur++;
	}

	return sum;
}

st bfs() {

	queue<st> que;
	que.push(st1);

	while (que.size()) {

		st t = que.front();


		for (int i = 1; i <= n; i++) {
			for (int j = 1; j <= n; j++) {

				if(t.s.size())
				    if (i == t.s.back().x&&j == t.s.back().y)
					    continue;

				st mid;

				clone(mid.map, t.map);//map

				change(i, j, mid.map);

				mid.a = make(mid.map);//a

				if (!jud[mid.a]) {

					jud[mid.a] = true;

					mid.num = t.num + 1;//num

					mid.s = t.s;//s

					mid.s.push_back({ i,j });

					que.push(mid);

					if (mid.a == 65535) {
						cout << mid.num << endl;
						return mid;
					}

				}

			}
		}
		que.pop();
	}

}


int main() {

	for(int i=1;i<=n;i++)
		for (int j = 1; j <= n; j++) {
			char a; cin >> a;
			if (a == '-') st1.map[i][j] = 1;
			else st1.map[i][j] = 0;
		}

	st1.a = make(st1.map);
	jud[st1.a] = 1;
	st1.num = 0;

	st it = bfs();

	for (int i = 0; i < it.s.size(); i++)
		cout << it.s[i].x << ' ' << it.s[i].y << endl;


}