A very hard Aoshu problem
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 943 Accepted Submission(s): 634
Problem Description
Aoshu is very popular among primary school students. It is mathematics, but much harder than ordinary mathematics for primary school students. Teacher Liu is an Aoshu teacher. He just comes out with a problem to test his students:
Given a serial of digits, you must put a ‘=‘ and none or some ‘+‘ between these digits and make an equation. Please find out how many equations you can get. For example, if the digits serial is "1212", you can get 2 equations, they are "12=12" and "1+2=1+2".
Please note that the digits only include 1 to 9, and every ‘+‘ must have a digit on its left side and right side. For example, "+12=12", and "1++1=2" are illegal. Please note that "1+11=12" and "11+1=12" are different equations.
Input
There are several test cases. Each test case is a digit serial in a line. The length of a serial is at least 2 and no more than 15. The input ends with a line of "END".
Output
For each test case , output a integer in a line, indicating the number of equations you can get.
Sample Input
Sample Output
Source
Recommend
zhoujiaqi2010 | We have carefully selected several similar problems for you:
5193 5192 5191 5190 5189
ac代码
#include<stdio.h>
#include<string.h>
char str[20];
int num[20][20];
int ans=0,len;
void dfs_r(int lsum,int pos,int rsum)
{
if(lsum==rsum&&pos==len)
{
ans++;
return;
}
for(int i=pos;i<len;i++)
{
dfs_r(lsum,i+1,rsum+num[pos][i]);
}
}
void dfs_l(int pos,int mid,int lsum)
{
if(pos==mid)
{
dfs_r(lsum,mid,0);
}
for(int i=pos;i<mid;i++)
{
dfs_l(i+1,mid,lsum+num[pos][i]);
}
}
int main()
{
while(scanf("%s",str)!=EOF)
{
int i,j,k;
if(strcmp(str,"END")==0)
break;
len=strlen(str);
memset(num,0,sizeof(num));
for(i=0;i<len;i++)
{
for(j=i;j<len;j++)
{
for(k=i;k<=j;k++)
{
num[i][j]=num[i][j]*10+(str[k]-'0');
}
// printf("%d %d %d\n",i,j,num[i][j]);
}
}
ans=0;
for(i=1;i<len;i++)
{
dfs_l(0,i,0);
}
printf("%d\n",ans);
}
}
HDOJ 题目A very hard Aoshu problem（暴力，DFS）
原文：http://blog.csdn.net/yu_ch_sh/article/details/44679373
