Worst ever played a kickstart last ks actually occurred before the winter camp of results = = felt his winter camp to cool the
reason is simply too unrealistic expectations of themselves, do a good B, C small data, but also AC will not last to the first question it
B title, I spent two hours there is no AC = =, the first similar to my approach and solution to a problem of big data.
- We can see that every point is only determined by two diagonal, then each diagonal up to do once, do it twice is equivalent to waste Well.
Then we found that if first discuss whether to take up a positive diagonal, that is, from (0,0) to (n-1, n-1), can be discussed directly with half the diagonal and trade-offs half points to 5 * 5, for example, as shown in FIG. For each element on the diagonal of the longest positive, if it is '.', It is necessary to use their corresponding anti-diagonal to turn over, than vice versa will not use these anti-diagonal. After that, if these are discussed anti-diagonal if there is '', then we need to draw on their alignment with the diagonal flip. After we then judge whether all the points have been reversed (all yellow dots drawing a picture far right weight)
We found that the step we discuss only half of the operating point and diagonal. For the other half, even-odd-length length of the side edge and discussion are slightly different (as shown, odd-length anti longest diagonal half of this side is not). But the same general direction, looking for the remaining points of the longest anti-diagonal one, then the second step and do a similar operation. We have to pay attention to the two-step discussion diagonal 2,3 not turn flip
Code = = details still look a little long to write
#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#include <map>
#include <bitset>
#include <algorithm>
#include <iomanip>
#include <cmath>
#include <ctime>
#include <functional>
#include <unordered_set>
#include <unordered_map>
#include <queue>
#include <deque>
#include <stack>
#include <complex>
#include <cassert>
#include <random>
#include <cstring>
#include <numeric>
#define mp make_pair
#define ll long long
#define ld long double
#define null NULL
#define all(a) a.begin(), a.end()
#define forn(i, n) for (int i = 0; i < n; ++i)
#define sz(a) (int)a.size()
#define lson l , m , rt << 1
#define rson m + 1 , r , rt << 1 | 1
#define bitCount(a) __builtin_popcount(a)
template<class T> int gmax(T &a, T b) { if (b > a) { a = b; return 1; } return 0; }
template<class T> int gmin(T &a, T b) { if (b < a) { a = b; return 1; } return 0; }
using namespace std;
string to_string(string s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string) s); }
string to_string(bool b) { return (b ? "true" : "false"); }
template <typename A, typename B>
string to_string(pair<A, B> p) { return "(" + to_string(p.first) + ", " + to_string(p.second) + ")"; }
template <typename A>
string to_string(A v) { bool first = true; string res = "{"; for (const auto &x : v) { if (!first) { res += ", "; } first = false; res += to_string(x); } res += "}"; return res; }
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) { cerr << " " << to_string(H); debug_out(T...); }
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
const int INF = 0x3f3f3f3f;
char seq[105][105];
int n;
int id1[105][105];
int id2[105][105];
int tmp[105][105];
vector<vector<pair<int, int> > > s1;
vector<vector<pair<int, int> > > s2;
void init() {
s1.clear(); s2.clear();
int cnt = 0;
for(int i = n-1; i >= 0; --i) {
int x = i; int y = 0;
vector<pair<int, int> > tmp;
while(1) {
id1[x][y] = cnt;
tmp.push_back(make_pair(x, y));
x ++; y ++;
if(x < 0 || x >= n || y < 0 || y >= n) break;
}
s1.push_back(tmp);
cnt ++;
}
for(int i = 1; i <= n-1; ++i) {
int x = 0; int y = i;
vector<pair<int, int> > tmp;
while(1) {
id1[x][y] = cnt;
tmp.push_back(make_pair(x, y));
x ++; y ++;
if(x < 0 || x >= n || y < 0 || y >= n) break;
}
s1.push_back(tmp);
cnt ++;
}
cnt = 0;
for(int i = 0; i <= n-1; ++i) {
int x = i; int y = 0;
vector<pair<int, int> > tmp;
while(1) {
id2[x][y] = cnt;
tmp.push_back(make_pair(x, y));
x --; y ++;
if(x < 0 || x >= n || y < 0 || y >= n) break;
}
s2.push_back(tmp);
cnt ++;
}
for(int i = 1; i <= n-1; ++i) {
int x = n-1; int y = i;
vector<pair<int, int> > tmp;
while(1) {
id2[x][y] = cnt;
tmp.push_back(make_pair(x, y));
x --; y ++;
if(x < 0 || x >= n || y < 0 || y >= n) break;
}
s2.push_back(tmp);
cnt ++;
}
// debug(s1, s2);
}
int solve1(int ty) {
// debug(ty);
int cnt = ty == 1; bool suc = true;
map<int, int> mp;
for(int i = 0; i < n; ++i) {
for(int j = 0; j < n; ++j) {
tmp[i][j] = seq[i][j] == '#';
}
}
vector<int> diagnol;
int target = s1.size() / 2;
for(int i = 0, len = s1[target].size(); i < len; ++i) {
int x = s1[target][i].first; int y = s1[target][i].second;
// debug(tmp[x][y], (ty == 1));
if(tmp[x][y] == (ty == 1) ) {
cnt ++;
diagnol.push_back(id2[x][y]);
// debug("yingying");
}
if(ty == 1) tmp[x][y] = !tmp[x][y];
}
// debug(diagnol);
for(int i = 0, len = diagnol.size(); i < len; ++i) {
for(int j = 0, len2 = s2[diagnol[i]].size(); j < len2; ++j) {
int x = s2[diagnol[i]][j].first; int y = s2[diagnol[i]][j].second;
// debug(x, y);
tmp[x][y] = !tmp[x][y];
}
}
for(int i = target % 2; i < s1.size();i += 2) {
for(auto Point : s1[i]) {
int x = Point.first; int y = Point.second;
if(tmp[x][y] == 0) {
// debug(x, y);
mp[id1[x][y]] ++;
}
}
}
for(auto it : mp) {
// debug(it.first, it.second);
cnt ++;
if(s1[it.first].size() != it.second) {
suc = false; break;
}
}
if(suc == true) {
// debug(cnt);
return cnt;
}
else return INF;
}
int solve2(int ty) {
int cnt = ty == 1; bool suc = true;
map<int, int> mp;
for(int i = 0; i < n; ++i) {
for(int j = 0; j < n; ++j) {
tmp[i][j] = seq[i][j] == '#';
}
}
vector<int> diagnol;
int target = s2.size() / 2;
if(n % 2) target --;
for(int i = 0, len = s2[target].size(); i < len; ++i) {
int x = s2[target][i].first; int y = s2[target][i].second;
if(tmp[x][y] == (ty == 1) ) {
cnt ++;
diagnol.push_back(id1[x][y]);
}
if(ty == 1) tmp[x][y] = !tmp[x][y];
}
// debug(diagnol);
for(int i = 0, len = diagnol.size(); i < len; ++i) {
for(int j = 0, len2 = s1[diagnol[i]].size(); j < len2; ++j) {
int x = s1[diagnol[i]][j].first; int y = s1[diagnol[i]][j].second;
tmp[x][y] = !tmp[x][y];
}
}
for(int i = 1; i < s2.size();i += 2) {
for(auto Point : s2[i]) {
int x = Point.first; int y = Point.second;
if(tmp[x][y] == 0) {
// debug(i, j)
mp[id2[x][y]] ++;
}
}
}
for(auto it : mp) {
cnt ++;
if(s2[it.first].size() != it.second) {
suc = false; break;
}
}
if(suc == true) return cnt;
else return INF;
}
int main() {
int T;
scanf("%d", &T);
for(int cas = 1; cas <= T; ++cas) {
scanf("%d", &n);
for(int i = 0; i < n; ++i) {
scanf("%s", seq[i]);
}
init();
printf("Case #%d: ", cas);
if(n == 1) {
printf("%d\n", seq[0][0] == '.');
continue;
}
printf("%d\n", min(solve1(1), solve1(0)) + min(solve2(1), solve2(0)) );
}
return 0;
}