1056.txt

浙江大学ａｃｍ试题的答案

#include<stdio.h>
#include<string.h>
#define N 101
int main()
{
	char s[N];
	int n,i,j,l,a[20][2],ah;
	bool b[50][50];
	while(1)
	{
		scanf("%d",&n);
		if(n==0)break;
		scanf("%s",s);
		memset(b,0,sizeof(b));
		for(i=10;i<30;i++)b[24][i]=1;
		l=strlen(s);
		ah=19;
		for(i=0;i<20;i++){a[i][0]=24;a[i][1]=10+i;}
		for(i=0;i<l;i++)
		{
			switch(s[i])
			{
			case 'E':
				if(a[ah][1]>=49)
				{printf("The worm ran off the board on move %d.\n",i+1);goto end;
					}
				if(b[a[ah][0]][a[ah][1]+1]&&(a[ah][0]!=a[(ah-19+20)%20][0]||a[ah][1]+1!=a[(ah-19+20)%20][1]))
				{printf("The worm ran into itself on move %d.\n",i+1);goto end;}
				j=ah;
				ah=(ah+1)%20;a[ah][0]=a[j][0];a[ah][1]=a[j][1]+1;
				break;
			case 'W':
				if(a[ah][1]==0)
				{printf("The worm ran off the board on move %d.\n",i+1);goto end;
					}
				if(b[a[ah][0]][a[ah][1]-1]&&(a[ah][0]!=a[(ah-19+20)%20][0]||a[ah][1]-1!=a[(ah-19+20)%20][1]))
				{printf("The worm ran into itself on move %d.\n",i+1);goto end;}
				j=ah;
				ah=(ah+1)%20;a[ah][0]=a[j][0];a[ah][1]=a[j][1]-1;
				break;
			case 'S':
				if(a[ah][0]>=49)
				{printf("The worm ran off the board on move %d.\n",i+1);goto end;
					}
				if(b[a[ah][0]+1][a[ah][1]]&&(a[ah][0]+1!=a[(ah-19+20)%20][0]||a[ah][1]!=a[(ah-19+20)%20][1]))
				{printf("The worm ran into itself on move %d.\n",i+1);goto end;}
				j=ah;
				ah=(ah+1)%20;a[ah][0]=a[j][0]+1;a[ah][1]=a[j][1];
				break;
			case 'N':
				if(a[ah][0]==0)
				{printf("The worm ran off the board on move %d.\n",i+1);goto end;
					}
				if(b[a[ah][0]-1][a[ah][1]]&&(a[ah][0]-1!=a[(ah-19+20)%20][0]||a[ah][1]!=a[(ah-19+20)%20][1]))
				{printf("The worm ran into itself on move %d.\n",i+1);goto end;}
				j=ah;
				ah=(ah+1)%20;a[ah][0]=a[j][0]-1;a[ah][1]=a[j][1];
				break;
			default:
				break;
			}
			memset(b,0,sizeof(b));
			for(j=0;j<20;j++)
				b[a[(ah-j+20)%20][0]][a[(ah-j+20)%20][1]]=1;
		}
		printf("The worm successfully made all %d moves.\n",i);
end:
		;
	}
	return 0;
}