POj 1145

伤不起呀

#include <stdio.h>
int n;
int flag;
char inputFilter()
{
	char c;
	while(scanf("%c",&c)&&c==' '||c=='\n'||c==9||c==10);
	return c;
}
int dfs(int sum,int height)
{   
   char c;

   int sign=1;
   int count=0;
   c=inputFilter();//个人认为此处是本题的关键点1
   if(c==')') return height;
   if(c=='-')
   {
	   sign=-1;
	   c=inputFilter();
   }
   while(c>='0'&&c<='9')
   {
	   count=count*10+sign*(c-'0');
	   scanf("%c",&c);
   }
   if(c=='\n'||c==' ') c=inputFilter();
   int k1=dfs(sum+count,height+1);
   c=inputFilter();
   int k2=dfs(sum+count,height+1);
   c=inputFilter();
   if(k1==height+1&&k2==height+1)//关键点2，判断终结点
   {
      if(sum+count==n) flag=1;
   }

   return 0;

}
int main()
{
	while(scanf("%d",&n)!=EOF)
	{
		flag=0;
		inputFilter();//使dfs第4 行的C读的是（后面的字符
		dfs(0,0);
		if(flag==1) printf("yes\n");
		else printf("no\n");
	}
	return 0;
}