牛客小白月赛34- E.dd爱旋转 - 群论思想

Posted 2021-06-08 Chivas_/Regal

思路：
这种大批量的操作题应该去记录操作的状态，避免不需要的操作

这应该是我第一次遇见这么浅显的群论题了（就算不了解群论也能发现的规律）
其实就是现实就能模拟出来的一个简单的规律
一个平面，顺时针旋转180°和上下翻转，无论哪个操作在前都不会改变最终的样式，而且每个操作进行两次都相当于没进行
所以我们依然可以让两个操作对2取模
然后为1的都进行一遍操作就行了

代码：

/*
           ________   _                                              ________                              _
          /  ______| | |                                            |   __   |                            | |
         /  /        | |                                            |  |__|  |                            | |
         |  |        | |___    _   _   _   ___  _   _____           |     ___|   ______   _____   ___  _  | |
         |  |        |  __ \\  |_| | | | | |  _\\| | | ____|          |  |\\  \\    |  __  | |  _  | |  _\\| | | |
         |  |        | |  \\ |  _  | | | | | | \\  | | \\___           |  | \\  \\   | |_/ _| | |_| | | | \\  | | |
         \\  \\______  | |  | | | | \\ |_| / | |_/  |  ___/ |          |  |  \\  \\  |    /_   \\__  | | |_/  | | |
Author :  \\________| |_|  |_| |_|  \\___/  |___/|_| |_____| _________|__|   \\__\\ |______|     | | |___/|_| |_|
                                                                                         ____| |
                                                                                         \\_____/
*/
//#include <unordered_map>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <utility>
#include <string>
#include <vector>
#include <cstdio>
#include <stack>
#include <queue>
#include <cmath>
#include <map>
#include <set>

#define G 10.0
#define LNF 1e18
#define EPS 1e-6
#define PI acos(-1.0)
#define INF 0x7FFFFFFF

#define ll long long
#define ull unsigned long long

#define LOWBIT(x) ((x) & (-x))
#define LOWBD(a, x) lower_bound(a.begin(), a.end(), x) - a.begin()
#define UPPBD(a, x) upper_bound(a.begin(), a.end(), x) - a.begin()
#define TEST(a) cout << "---------" << a << "---------" << '\\n'

#define CHIVAS int main()
#define _REGAL exit(0)

#define SP system("pause")
#define IOS ios::sync_with_stdio(false)
//#define map unordered_map

#define _int(a) int a; cin >> a
#define  _ll(a) ll a; cin >> a
#define _char(a) char a; cin >> a
#define _string(a) string a; cin >> a
#define _vectorInt(a, n) vector<int>a(n); cin >> a
#define _vectorLL(a, b) vector<ll>a(n); cin >> a

#define PB(x) push_back(x)
#define ALL(a) a.begin(),a.end()
#define MEM(a, b) memset(a, b, sizeof(a))
#define EACH_CASE(cass) for (cin >> cass; cass; cass--)

#define LS l, mid, rt << 1
#define RS mid + 1, r, rt << 1 | 1
#define GETMID (l + r) >> 1

using namespace std;

template<typename T> inline void Read(T &x){T f = 1; x = 0;char s = getchar();while(s < '0' || s > '9'){if(s == '-') f = -1; s = getchar();}while('0'<=s&&s<='9'){x=(x<<3)+(x<<1)+(s^48);s=getchar();}x*=f;}
template<typename T> inline T MAX(T a, T b){return a > b? a : b;}
template<typename T> inline T MIN(T a, T b){return a > b? b : a;}
template<typename T> inline void SWAP(T &a, T &b){T tp = a; a = b; b = tp;}
template<typename T> inline T GCD(T a, T b){return b > 0? GCD(b, a % b) : a;}
template<typename T> inline void ADD_TO_VEC_int(T &n, vector<T> &vec){vec.clear(); cin >> n; for(int i = 0; i < n; i ++){T x; cin >> x, vec.PB(x);}}
template<typename T> inline pair<T, T> MaxInVector_ll(vector<T> vec){T MaxVal = -LNF, MaxId = 0;for(int i = 0; i < (int)vec.size(); i ++) if(MaxVal < vec[i]) MaxVal = vec[i], MaxId = i; return {MaxVal, MaxId};}
template<typename T> inline pair<T, T> MinInVector_ll(vector<T> vec){T MinVal = LNF, MinId = 0;for(int i = 0; i < (int)vec.size(); i ++) if(MinVal > vec[i]) MinVal = vec[i], MinId = i; return {MinVal, MinId};}
template<typename T> inline pair<T, T> MaxInVector_int(vector<T> vec){T MaxVal = -INF, MaxId = 0;for(int i = 0; i < (int)vec.size(); i ++) if(MaxVal < vec[i]) MaxVal = vec[i], MaxId = i; return {MaxVal, MaxId};}
template<typename T> inline pair<T, T> MinInVector_int(vector<T> vec){T MinVal = INF, MinId = 0;for(int i = 0; i < (int)vec.size(); i ++) if(MinVal > vec[i]) MinVal = vec[i], MinId = i; return {MinVal, MinId};}
template<typename T> inline pair<map<T, T>, vector<T> > DIV(T n){T nn = n;map<T, T> cnt;vector<T> div;for(ll i = 2; i * i <= nn; i ++){while(n % i == 0){if(!cnt[i]) div.push_back(i);cnt[i] ++;n /= i;}}if(n != 1){if(!cnt[n]) div.push_back(n);cnt[n] ++;n /= n;}return {cnt, div};}
template<typename T>             vector<T>& operator--            (vector<T> &v){for (auto& i : v) --i;            return  v;}
template<typename T>             vector<T>& operator++            (vector<T> &v){for (auto& i : v) ++i;            return  v;}
template<typename T>             istream& operator>>(istream& is,  vector<T> &v){for (auto& i : v) is >> i;        return is;}
template<typename T>             ostream& operator<<(ostream& os,  vector<T>  v){for (auto& i : v) os << i << ' '; return os;}

int Map[1100][1100];
int cnt1 = 0, cnt2 = 0;//操作1的数量，操作2的数量

inline void solve(){
        int n; scanf("%d", &n);
        for(int i = 0; i < n; i ++){
                for(int j = 0; j < n; j ++){
                        scanf("%d", &Map[i][j]);
                }
        }
        int q; scanf("%d", &q);
        while(q --){
                int x; scanf("%d", &x);
                cnt1 += (x == 1);
                cnt2 += (x == 2);
        }
        cnt1 %= 2;
        cnt2 %= 2;
        
        if(cnt1){//操作1：顺时针旋转180°
                for(int i = 0; i < n; i ++){
                        for(int j = 0; j < i; j ++){
                                SWAP(Map[i][j], Map[n - i - 1][n - j - 1]);
                        }
                }
                for(int i = 0; i < n / 2; i ++){
                        SWAP(Map[i][i], Map[n - i - 1][n - i - 1]);
                }
        }
        if(cnt2){//操作2：上下翻转
                for(int i = 0; i < n / 2; i ++){
                        for(int j = 0; j < n; j ++){
                                SWAP(Map[i][j], Map[n - i - 1][j]);
                        }
                }
        }
        
        for(int i = 0; i < n; i ++){
                for(int j = 0; j < n; j ++){
                        if(j != 0) printf(" ");
                        printf("%d", Map[i][j]);
                }printf("\\n");
        }
}

CHIVAS{
        solve();
        _REGAL;
}