1056.cpp

zju 1056 The Worm Turns http://acm.zju.edu.cn/show_problem.php?pid=1056

#include <iostream>
using namespace std;
int main()
{
	int a[50][50],m,x1,y1,x2,y2,i,j,k;
	char c;
	cin>>m;
	while (m!=0)
	{
		for(x1=0;x1<50;x1++)
			for (y1=0;y1<50;y1++)
				a[x1][y1]=0;
		for (x1=10;x1<29;x1++)
			a[x1][24]=1;
		x1=29;y1=24;x2=10;y2=24;k=0;
		for (i=0;i<m;i++)
		{
			cin>>c;
			k++;
			switch (c)
			{
			case 'E':a[x1][y1]=1;x1=x1+1;break;
			case 'W':a[x1][y1]=2;x1=x1-1;break;
			case 'N':a[x1][y1]=3;y1=y1-1;break;
			case 'S':a[x1][y1]=4;y1=y1+1;break;
			}
			switch (a[x2][y2])
			{
			case 1:a[x2][y2]=0;x2=x2+1;break;
			case 2:a[x2][y2]=0;x2=x2-1;break;
			case 3:a[x2][y2]=0;y2=y2-1;break;
			case 4:a[x2][y2]=0;y2=y2+1;break;
			}
			if (x1>=0 && x1<50 && y1>=0 && y1<50)
			{
				if (a[x1][y1]==0) 
				{
					if (i+1==m) cout<<"The worm successfully made all "<<k<<" moves.\n";
					continue;
				}
				else cout<<"The worm ran into itself on move "<<k<<".\n";
			}
			else cout<<"The worm ran off the board on move "<<k<<".\n";
			for (j=i;j<m-1;j++) 
			{
				cin>>c;
				i++;
			}
		}
		cin>>m;
	}
	return 0;
}