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；
1 #define IOS ios_base::sync_with_stdio(0); cin.tie(0); 2 #include <cstdio>//sprintf islower isupper 3 #include <cstdlib>//malloc exit strcat itoa system("cls") 4 #include <iostream>//pair 5 #include <fstream> 6 #include <bitset> 7 //#include <map> 8 //#include<unordered_map> 9 #include <vector> 10 #include <stack> 11 #include <set> 12 #include <string.h>//strstr substr 13 #include <string> 14 #include <time.h>//srand(((unsigned)time(NULL))); Seed n=rand()%10 - 0~9; 15 #include <cmath> 16 #include <deque> 17 #include <queue>//priority_queue<int, vector<int>, greater<int> > q;//less 18 #include <vector>//emplace_back 19 //#include <math.h> 20 //#include <windows.h>//reverse(a,a+len);// ~ ! ~ ! floor 21 #include <algorithm>//sort + unique : sz=unique(b+1,b+n+1)-(b+1);+nth_element(first, nth, last, compare) 22 using namespace std;//next_permutation(a+1,a+1+n);//prev_permutation 23 #define fo(a,b,c) for(register int a=b;a<=c;++a) 24 #define fr(a,b,c) for(register int a=b;a>=c;--a) 25 #define mem(a,b) memset(a,b,sizeof(a)) 26 #define pr printf 27 #define sc scanf 28 #define ls rt<<1 29 #define rs rt<<1|1 30 void swapp(int &a,int &b); 31 double fabss(double a); 32 int maxx(int a,int b); 33 int minn(int a,int b); 34 int Del_bit_1(int n); 35 int lowbit(int n); 36 int abss(int a); 37 //const long long INF=(1LL<<60); 38 const double E=2.718281828; 39 const double PI=acos(-1.0); 40 const int inf=(1<<29); 41 const double ESP=1e-9; 42 const int mod=(int)1e9+7; 43 const int N=(int)1e6+10; 44 45 int mp[1030][1030]; 46 47 void same(int cnt) 48 { 49 fo(i,1,cnt) 50 { 51 fo(j,1,cnt) 52 { 53 mp[i][j+cnt]=mp[i][j]; 54 } 55 } 56 } 57 58 void _(int cnt) 59 { 60 fo(i,cnt+1,cnt*2-1) 61 { 62 fo(j,1,cnt) 63 mp[i][j]=mp[i-cnt+1][j]; 64 fo(j,cnt+1,cnt*2) 65 mp[i][j]=1-mp[i-cnt+1][j]; 66 } 67 fo(i,1,cnt) 68 mp[cnt*2][i]=1; 69 fo(i,cnt+1,cnt*2) 70 mp[cnt*2][i]=0; 71 } 72 73 int main() 74 { 75 mp[1][1]=mp[1][2]=mp[2][1]=1; 76 int cnt=2; 77 fo(i,2,10) 78 { 79 same(cnt); 80 _(cnt); 81 cnt*=2; 82 } 83 int n; 84 sc("%d",&n); 85 fo(i,1,n) 86 fo(j,1,n) 87 pr("%d%c",mp[i][j]==1?mp[i][j]:-1,j==n?' ':' '); 88 return 0; 89 } 90 91 /**************************************************************************************/ 92 93 int maxx(int a,int b) 94 { 95 return a>b?a:b; 96 } 97 98 void swapp(int &a,int &b) 99 { 100 a^=b^=a^=b; 101 } 102 103 int lowbit(int n) 104 { 105 return n&(-n); 106 } 107 108 int Del_bit_1(int n) 109 { 110 return n&(n-1); 111 } 112 113 int abss(int a) 114 { 115 return a>0?a:-a; 116 } 117 118 double fabss(double a) 119 { 120 return a>0?a:-a; 121 } 122 123 int minn(int a,int b) 124 { 125 return a<b?a:b; 126 }