记录编号	114520	评测结果	AAAAAAA
题目名称	[USACO 2.3.3]零数列	最终得分	100
用户昵称	HouJikan	是否通过	通过
代码语言	C++	运行时间	0.002 s
提交时间	2014-07-31 13:32:11	内存使用	0.31 MiB

#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <list>
#include <vector>
#include <ctime>
#include <functional>
#define pritnf printf
#define scafn scanf
#define For(i,j,k) for(int i=(j);i<=(k);(i)++)
using namespace std;
typedef long long LL;
typedef unsigned int Uint; 
const int INF=0x7ffffff;
//==============struct declaration==============

//==============var declaration=================
int n;
char ch[20];
//==============function declaration============
void dfs(int depth);
bool check();
void print();
//==============main code=======================
int main()
{  
  freopen("zerosum.in","r",stdin);
  freopen("zerosum.out","w",stdout); 

  cin>>n;
  dfs(1);
  return 0;
}
//================fuction code====================
void dfs(int depth)
{
  if (depth==n)
  {
    if (check())
      print();
    return ;
  }
  ch[depth]=' ';
  dfs(depth+1);
  ch[depth]='+';
  dfs(depth+1);
  ch[depth]='-';
  dfs(depth+1);
  return;
}
bool check()
{
  int sum=0;
  int now=0;
  int mul=1;
  ch[n]='+';
  For(i,1,n)
  {
    now=now*10+i;
    if (ch[i]!=' ')
    {
      sum+=mul*now;
      now=0;
      if (ch[i]=='+')
        mul=1;
      else if (ch[i]=='-')
        mul=-1;
    }
  }
  return (sum==0);
}
void print()
{
  For(i,1,n-1)
    pritnf("%d%c",i,ch[i]);
  printf("%d\n",n);
}