Turn OverGame - NDDCoder

#include<iostream>

using namespace std;
int board[4][4];
int minScore;

int isAllColor(){
	int c=board[0][0];
	for (int i=0;i<4;i++){
		for (int j=0;j<4;j++){
			if (board[i][j]!=c) return 0;
		}
	}
	return 1;
}

int calculate(){
	int b=0;
	int w=0;
	for (int i=0;i<4;i++){
		for (int j=0;j<4;j++){
			if (board[i][j]==0) w++;
			else b++;
		}
	}
	if (b==0 || w==0) return 1;
	return 0;
}

void turn(int i, int j){
	if (i>3||j>3) return;
	board[i][j] = 1-board[i][j];
	if (i>0) board[i-1][j]=1-board[i-1][j];
	if (i<3) board[i+1][j]=1-board[i+1][j];
	if (j>0) board[i][j-1]=1-board[i][j-1];
	if (j<3) board[i][j+1]=1-board[i][j+1];
}

void printBoard(){
	for (int i=0;i<4;i++){
		for (int j=0;j<4;j++){
			cout<<board[i][j];
		}
		cout<<endl;
	}
	cout<<endl;
}

void Try(int step, int startX, int startY){
	if (minScore != -1 && step > minScore) return;
//	if (step < 3){
//		cout<<step<<" "<<startX<<" "<<startY<<endl;
//		printBoard();
//	}
	if (isAllColor()){
		if (minScore == -1 || minScore>step) minScore = step;
		return;
	}
	if (startX > 3 || startY > 3) return;
	if (startY == 3) Try(step, startX+1, 0);
	else Try(step, startX, startY+1);
	turn(startX, startY);
	if (startY == 3) Try(step+1, startX+1, 0);
	else Try(step+1, startX, startY+1);
	turn(startX, startY);
}

int main(){
	freopen("TurnOverGame.txt","r",stdin);
	ios::sync_with_stdio(false);
	int T;
	cin>>T;
	for (int tc=1;tc<=T;tc++){
		cout<<"Case #"<<tc<<endl;
		for (int i=0;i<4;i++){
			for (int j=0;j<4;j++){
				char tmp;
				cin>>tmp;
				if (tmp=='b') board[i][j]=1;
				else board[i][j]=0;
			}
		}
//		if (tc!=20) continue;
		minScore = -1;
		Try(0, 0, 0);
		if (minScore !=-1) cout<<minScore<<endl;
		else cout<<"impossible"<<endl;
	}
}