PlayingChess688.cpp

#include <iostream>
#include <string>
#include <queue>
using namespace std;
char arr[8][8];
struct index {
	int row;
	int col;
};
queue <index>q;
int check(int row, int col) {
	if (row >= 0 && row <= 7 && col >= 0 && col <= 7 && (arr[row][col] == '-'|| arr[row][col] == '@')) {
		index in;
		in.row = row;
		in.col = col;
		q.push(in);
		if (arr[row][col] == '@')
			return 1;
		arr[row][col] = '*';
		return 0;
	}
	return 0;
}
int main() {
	int t = 0;
	string input;
	cin >> t;
	for (int i = 1; i <= t; i++) {
		index start;
		index end;
		q = queue <index>();
		for (int j = 0; j < 8; j++) {
			getline(cin, input);
			if(input[0]=='\0'|| input[0] == '\n')
				getline(cin, input);
			for (int k = 0; k < 8; k++) {
				arr[j][k] = input[k];
				if (input[k] == '#') {
					start.row = j;
					start.col = k;
				}
				else if (input[k] == '@') {
					end.row = j;
					end.col = k;
				}
			}
		}
		int ctr = 0;
		q.push(start);
		bool flag = true;
		bool flag1 = true;
		arr[start.row][start.col] = '0';
		int count = q.size();
		while (!q.empty()) {
			if (--count == 0) {//ignore the root
				if (flag == true) {
					count++;
					flag = false;
				}
				else {
					ctr++;
					count = q.size();
				}
			}
			index temp = q.front();
			q.pop();
			if (temp.row == end.row && temp.col == end.col) {
				flag1 = false;
				break;
			}
			int row;
			int col;
			int flag = 0;
			row = temp.row - 2;
			col = temp.col - 1;
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row - 1;
			col = temp.col - 2;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row + 2;
			col = temp.col + 1;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row + 1;
			col = temp.col + 2;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row + 2;
			col = temp.col - 1;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row + 1;
			col = temp.col - 2;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row - 2;
			col = temp.col + 1;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}

			row = temp.row - 1;
			col = temp.col + 2;
			check(row, col);
			flag = check(row, col);
			if (flag == 1) {
				ctr++;
				flag1 = false;
				break;
			}
			if (count == 0) {
				count = q.size();
			}	
		}
		cout << "Case " << i << ": ";
		if (flag1) {
			cout << "IMPOSSIBLE" << endl;
		}
		else
			cout << ctr << endl;
	}
	return 0;
}