两两内积为0（牛客多校第七场）-- CDMA

题意：

构造一个n*n的矩阵，元素只能是-1或1，任意两行内积为0（两两相乘加起来和为0）。

思路；

 #define IOS ios_base::sync_with_stdio(0); cin.tie(0);
 #include <cstdio>//sprintf islower isupper
 #include <cstdlib>//malloc  exit strcat itoa system("cls")
 #include <iostream>//pair
 #include <fstream>
 #include <bitset>
 //#include <map>
 //#include<unordered_map>
 #include <vector>
 #include <stack>
 #include <set>
 #include <string.h>//strstr substr
 #include <string>
 #include <time.h>//srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9;
 #include <cmath>
 #include <deque>
 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less
 #include <vector>//emplace_back
 //#include <math.h>
 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor
 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare)
 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation
 #define fo(a,b,c) for(register int a=b;a<=c;++a)
 #define fr(a,b,c) for(register int a=b;a>=c;--a)
 #define mem(a,b) memset(a,b,sizeof(a))
 #define pr printf
 #define sc scanf
 #define ls rt<<1
 #define rs rt<<1|1
 void swapp(int &a,int &b);
 double fabss(double a);
 int maxx(int a,int b);
 int minn(int a,int b);
 int Del_bit_1(int n);
 int lowbit(int n);
 int abss(int a);
 //const long long INF=(1LL<<60);
 const double E=2.718281828;
 const double PI=acos(-1.0);
 const int inf=(<<);
 const double ESP=1e-;
 const int mod=(int)1e9+;
 const int N=(int)1e6+;

 int mp[][];

 void same(int cnt)
 {
     fo(i,,cnt)
     {
         fo(j,,cnt)
         {
             mp[i][j+cnt]=mp[i][j];
         }
     }
 }

 void _(int cnt)
 {
     fo(i,cnt+,cnt*-)
     {
         fo(j,,cnt)
             mp[i][j]=mp[i-cnt+][j];
         fo(j,cnt+,cnt*)
             mp[i][j]=-mp[i-cnt+][j];
     }
     fo(i,,cnt)
         mp[cnt*][i]=;
     fo(i,cnt+,cnt*)
         mp[cnt*][i]=;
 }

 int main()
 {
     mp[][]=mp[][]=mp[][]=;
     int cnt=;
     fo(i,,)
     {
         same(cnt);
         _(cnt);
         cnt*=;
     }
     int n;
     sc("%d",&n);
     fo(i,,n)
         fo(j,,n)
             pr("%d%c",mp[i][j]==?mp[i][j]:-,j==n?'\n':' ');
     return ;
 }

 /**************************************************************************************/

 int maxx(int a,int b)
 {
     return a>b?a:b;
 }

 void swapp(int &a,int &b)
 {
     a^=b^=a^=b;
 }

 int lowbit(int n)
 {
     return n&(-n);
 }

 int Del_bit_1(int n)
 {
     return n&(n-);
 }

 int abss(int a)
 {
     return a>?a:-a;
 }

 double fabss(double a)
 {
     return a>?a:-a;
 }

 int minn(int a,int b)
 {
     return a<b?a:b;
 }