Bzoj 1800: [Ahoi2009]fly Flight chess violence

1800: [Ahoi2009]fly flying Chess

Time Limit:1 Sec

Memory limit:256 MB

Topic Connection http://www.lydsy.com/JudgeOnline/problem.php?id=1800
Description

Given a number of points on the circumference, the arc length between the point and the point is known, and the values are positive integers, arranged in a circular order. Please find out if there are any rectangles in these points and hope to find all the non-repeating rectangles in the shortest time.

Input

The first action is an integer n, which represents the number of points, and the next n rows are the individual arc lengths divided by the N points.

Output

The number of non-repeating rectangles that are formed

Sample Input8
1
2
2
3
1
1
3
3

Sample Output

3HINT

n<= 20

Test instructions

Exercises

The data range is only 20, then the direct violence is good ~

Code:

//Qscqesze#pragmaComment (linker, "/stack:1024000000,1024000000")#include<cstdio>#include<cmath>#include<cstring>#include<ctime>#include<iostream>#include<algorithm>#include<Set>#include<bitset>#include<vector>#include<sstream>#include<queue>#include<typeinfo>#include<fstream>#include<map>#include<stack>typedefLong Longll;using namespacestd;//freopen ("d.in", "R", stdin);//freopen ("D.out", "w", stdout);#defineSspeed ios_base::sync_with_stdio (0); Cin.tie (0)#defineMAXN 40#defineMoD 1001#defineEPS 1e-9#definePi 3.1415926intNum;//const int INF=0X7FFFFFFF;Constll inf=999999999; inline ll read () {ll x=0, f=1;CharCh=GetChar ();  while(ch<'0'|| Ch>'9'){if(ch=='-') f=-1; ch=GetChar ();}  while(ch>='0'&&ch<='9') {x=x*Ten+ch-'0'; ch=GetChar ();} returnx*F;}//*************************************************************************************intA[MAXN];intMain () {intn=read ();  for(intI=1; i<=n;i++) A[i]=read (), a[i]+=a[i-1]; intAns =0;  for(intI=1; i<=n;i++)     for(intj=i+1; j<=n;j++)     for(intk=j+1; k<=n;k++)     for(intt=k+1; t<=n;t++)        if(a[j]-a[i]==a[t]-a[k]&& (a[n]+a[i]-a[t]) ==a[k]-A[j]) ans++; printf ("%d\n", ans);}

Bzoj 1800: [Ahoi2009]fly Flight chess violence