How Many Equations Can You Find 2266 （深搜 dfs）

How Many Equations Can You Find

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 716    Accepted Submission(s): 469

Problem Description

Now give you an string which only contains 0, 1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,9.You are asked to add the sign ‘+’ or ’-’ between the characters. Just like give you a string “12345”, you can work out a string “123+4-5”. Now give you an integer N, please tell me how many ways can you find to make the result of the string equal to N .You can only choose at most one sign between two adjacent characters.

Input

Each case contains a string s and a number N . You may be sure the length of the string will not exceed 12 and the absolute value of N will not exceed 999999999999.

Output

The output contains one line for each data set : the number of ways you can find to make the equation.

Sample Input

123456789 3
211

Sample Output

18 1

 

#include<stdio.h>
#include<string.h>
char s[15];
int n,num,l;
void dfs(int x,int m)
{
	if(x==l)
	{
		if(m==n)
			num++;
		return ;
	}
	else
	{
		int mm=0;
		for(int i=x;i<l;i++)
		{
			mm=mm*10+s[i]-'0';
			dfs(i+1,mm+m);
			if(x!=0)
				dfs(i+1,m-mm);
		}
	}
}
int main()
{
	while(scanf("%s",s)!=EOF)
	{
		scanf("%d",&n);
		l=strlen(s);
		num=0;
		dfs(0,0);
		printf("%d\n",num);
	}
	return 0;
}