#include<stdio.h>

int data[1000000];
int main()
{
	int m,n,i,j;
	while(scanf("%d %d",&m,&n)==2){
		if(!m && !n)
			return 0;
		for(i = 0; i < m*n; i++)
				scanf("%d",&data[i]);
			int ni = 0;
			for(i = 0; i < m*n-1; i++)
				for(j = i+1; j < m*n; j++)
					if(data[i] > data[j] && data[j] != 0)
						ni++;
			if(ni%2 == 0)
				printf("YES\n");
			else
				printf("NO\n");
	}
}

• 还要加上0到目标位置的步数吧。另外这样做不WA也会TLE吧…… (447) rovingcloud 2006-07-31 01:42:34