记录编号	123171	评测结果	AAAAAAAAAA
题目名称	多米诺骨牌	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	1.170 s
提交时间	2014-09-25 22:43:44	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 <iterator>
#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==============
struct adj
{
  int to,dist;
  adj (int to=0,int dist=0):to(to),dist(dist){}
};
//==============var declaration=================
const int MAXN=1010;
map <int,int> pre,now;
int n,up,down;
//==============function declaration============
inline int abs(int x){return x<0?-x:x;}
//==============main code=======================
int main()
{  
  string FileName="dom";//程序名 
  string FloderName="COGS";//文件夹名 
  freopen((FileName+".in").c_str(),"r",stdin);
  freopen((FileName+".out").c_str(),"w",stdout);
  ios::sync_with_stdio(false);
#ifdef DEBUG  
  system(("cp C:\\Users\\Administrator\\Desktop\\"+FloderName+"\\standard.cpp C:\\Users\\Administrator\\Desktop\\"+FloderName+"\\submit.txt").c_str());
  clock_t Start_Time=clock();
#endif    
  cin>>n;
  pre[0]=0;
  map<int,int>::iterator it,endit;
  int T;
  For(i,1,n)
  {
    cin>>up>>down;
    endit=pre.end();
    for(it=pre.begin();it!=endit;++it){
      T=it->first+up-down;//不转 
      if (!now.count(T)||now[T]>it->second)
        now[T]=it->second;
      T=it->first-up+down;//转 
      if (!now.count(T)||now[T]>it->second+1)
        now[T]=it->second+1;
    }
    pre=now;
    now.clear();
  }
  int x=INF,d=INF;
  for(it=pre.begin(),endit=pre.end();it!=endit;++it){
    if (abs(it->first)<abs(x)){
      x=it->first;
      d=INF;
    }
    if (abs(it->first)==abs(x))
      d=min(d,it->second);
  }
  cout<<d<<endl;
#ifdef DEBUG  
  clock_t End_Time=clock();
  printf("\n\nTime Used: %.4lf Ms\n",double(End_Time-Start_Time)/CLOCKS_PER_SEC);
#endif    
  return 0;
}
//================fuction code====================