8.27 网易互娱笔试
第一题：
int main() {
int c;
cin >> c;
while (c--) {
int n, m;
cin >> n >> m;
vector<string> v(n, string(n, ' '));
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
cin >> v[i][j];
}
}
for (int i = 0; i < m; i++) {
for (int j = 0; j < m; j++) {
putchar(v[(abs(i - m / 2) % n + n / 2) % n][(abs(j - m / 2) % n + n / 2) % n]);
}
putchar('\n');
}
putchar('\n');
}
} 第三题 ：总共有28种小图案，dfs然后用位图记录图案是否出现，放到unordered_set去重
#include <iostream>
#include <vector>
#include <unordered_set>
#include <assert.h>
using namespace std;
void add(long long& flag, int a, int b) {
if (a > b) swap(a, b);
assert(a < b);
if (a == 1) {
switch (b){
case 2: flag |= 1; break;//
case 3: flag |= 3; break;//
case 4: flag |= 1 << 6; break;//
case 5: flag |= 1 << 12; break;
case 6: flag |= 1 << 20; break; //
case 7: flag |= (1 << 6) | (1 << 9); break;//
case 8: flag |= 1 << 24; break; //
case 9: flag |= (1 << 12) | (1 << 15); break; //
default: assert(0);
}
}
if (a == 2) {
switch (b){
case 3: flag |= 2; break;//
case 4: flag |= 1 << 16; break; //
case 5: flag |= 1 << 7; break;//
case 6: flag |= 1 << 13; break; //
case 7: flag |= 1 << 26; break; //
case 8: flag |= (1 << 7) | (1 << 10); break;//
case 9: flag |= 1 << 25; break; //
default: assert(0);
}
}
if (a == 3) {
switch (b){
case 4: flag |= 1 << 22; break; //
case 5: flag |= 1 << 17; break; //
case 6: flag |= 1 << 8; break;//
case 7: flag |= (1 << 17) | (1 << 18); break; //
case 8: flag |= 1 << 27; break; //
case 9: flag |= (1 << 8) | (1 << 11); break;//
default: assert(0);
}
}
if (a == 4) {
switch (b){
case 5: flag |= 1 << 2; break;//
case 6: flag |= (1 << 2) | (1 << 3); break;//
case 7: flag |= 1 << 9; break;//
case 8: flag |= 1 << 14; break; //
case 9: flag |= 1 << 21; break; //
default: assert(0);
}
}
if (a == 5) {
switch (b){
case 6: flag |= 1 << 3; break;//
case 7: flag |= 1 << 18; break;//
case 8: flag |= 1 << 10; break;//
case 9: flag |= 1 << 15; break; //
default: assert(0);
}
}
if (a == 6) {
switch (b){
case 7: flag |= 1 << 23; break;//
case 8: flag |= 1 << 19; break; //
case 9: flag |= 1 << 11; break;//
default: assert(0);
}
}
if (a == 7) {
switch (b){
case 8: flag |= 1 << 4; break;//
case 9: flag |= (1 << 4) | (1 << 5); break;//
default: assert(0);
}
}
if (a == 8) {
switch (b){
case 9: flag |= 1 << 5; break;//
default: assert(0);
}
}
}
void dfs(vector<int>& v, int idx, int n, long long flag, unordered_set<long long>& uset) {
if (idx > 1) {
add(flag, v[idx - 1], v[idx - 2]);
uset.insert(flag);
}
if (idx == n) return;
for (int i = idx; i < n; i++) {
swap(v[i], v[idx]);
dfs(v, idx + 1, n, flag, uset);
swap(v[i], v[idx]);
}
}
int main() {
int a;
cin >> a;
int n;
while (a--) {
vector<int> v;
for (int i = 0; i < 9; i++) {
char c;
cin >> c;
if (c == '.') v.push_back(i + 1);
}
unordered_set<long long> uset;
dfs(v, 0, v.size(), 0, uset);
cout << uset.size() << endl;
}
} 
