题目链接:
time limit per test
1 secondmemory limit per test
256 megabytesinput
standard inputoutput
standard outputAt a geometry lesson Gerald was given a task: to get vector B out of vector A. Besides, the teacher permitted him to perform the following operations with vector А:
- Turn the vector by 90 degrees clockwise.
- Add to the vector a certain vector C.
Operations could be performed in any order any number of times.
Can Gerald cope with the task?
Input
The first line contains integers x1 и y1 — the coordinates of the vector A ( - 108 ≤ x1, y1 ≤ 108). The second and the third line contain in the similar manner vectors B and C (their coordinates are integers; their absolute value does not exceed 108).
Output
Print "YES" (without the quotes) if it is possible to get vector B using the given operations. Otherwise print "NO" (without the quotes).
Examples
input
0 0
1 1
0 1
output
YES
input
0 0
1 1
1 1
output
YES
input
0 0
1 1
2 2
output
NO
题意:
两个操作,1把A向量旋转90度,2把C向量加到A向量上,现在两个操作可以执行任意多次,顺序也是任意的,问能否得到B向量;
思路:
假设D为C旋转90度的向量,E为A旋转后的向量;
可以发现最后得到的都是a*C+b*D=B-E;
这就变成了一个判断一个二元一次方程组是否有整数解的问题;
那么就判断好了;
AC代码:
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <bits/stdc++.h> #include <stack> #include <map> using namespace std; #define For(i,j,n) for(int i=j;i<=n;i++) #define mst(ss,b) memset(ss,b,sizeof(ss)); typedef long long LL; template<class T> void read(T&num) { char CH; bool F=false; for(CH=getchar();CH<'0'||CH>'9';F= CH=='-',CH=getchar()); for(num=0;CH>='0'&&CH<='9';num=num*10+CH-'0',CH=getchar()); F && (num=-num); } int stk[70], tp; template<class T> inline void print(T p) { if(!p) { puts("0"); return; } while(p) stk[++ tp] = p%10, p/=10; while(tp) putchar(stk[tp--] + '0'); putchar(' '); } const LL mod=1e9+7; const double PI=acos(-1.0); const LL inf=1e18; const int N=(1<<20)+10; const int maxn=1e6+10; const double eps=1e-12; LL ax,ay,bx,by,cx,cy; int solve(LL x,LL y) { x=bx-x;y=by-y; if(cx==0&&cy==0) { if(x==0&&y==0)return 1; return 0; } else if(cx==0) { LL g=x/cy,h=y/cy; if(g*cy==x&&h*cy==y)return 1; return 0; } else if(cy==0) { LL g=x/cx,h=y/cx; if(g*cx==x&&h*cx==y)return 1; return 0; } else { LL tx=x*cy,ty=y*cx; LL b=(tx-ty)/(cy*cy+cx*cx); if(b*(cx*cx+cy*cy)!=(tx-ty))return 0; else { LL a=(x-b*cy)/cx; if(a*cx+b*cy==x)return 1; return 0; } } } int main() { read(ax);read(ay); read(bx);read(by); read(cx);read(cy); int f=0; if(solve(ax,ay))f=1; if(solve(-ax,-ay))f=1; if(solve(ay,-ax))f=1; if(solve(-ay,ax))f=1; if(f)cout<<"YES "; else cout<<"NO "; return 0; }