diff_Main.cpp

diff --git a/CodeJam/Main.cpp b/examples/2019/KS_H/B/Main.cpp
index 2150379..f6f17e9 100644
--- a/CodeJam/Main.cpp
+++ b/examples/2019/KS_H/B/Main.cpp
@@ -1570,11 +1570,69 @@ void init(){
     cin >> T;
 }
 
+ll N;
+v(v(bool)) grid;
+
 void readInput(){
+    cin >> N;
+    grid.cl;
+    grid.resize(N);
+    forn(i,N){
+        str t;
+        cin >> t;
+        grid[i].resize(N);
+        forn(j,N){
+            grid[i][j] = t[j] == '#';
+        }
+    }
 }
 
 // write to COMM_TYPE result
 void calcFunction() {
+    ll result_diag = 0;
+    ll result_offdiag = 0;
+
+    // first diag
+    forn(i, N){
+        if(!grid[i][i]){
+            result_diag++;
+            grid[i][i]=!grid[i][i];
+            ll k = 1;
+            while(i+k<N && i-k>=0){
+                grid[i+k][i-k]=!grid[i+k][i-k];
+                grid[i-k][i+k]=!grid[i-k][i+k];
+                k++;
+            }
+        }
+    }
+    forn(i, (N+1)/2 - 1){
+        if(!grid[0][2*i+2])
+            result_diag++;
+        if(!grid[2*i+2][0])
+            result_diag++;
+    }
+    // now offdiag
+    ll off = N%2;
+    forn(i,N-off){
+        if(!grid[i][N-1-i-off]){
+            result_offdiag++;
+            ll k=max(-i,off+i+1-N);
+            while(i+k<N && k<1+i+off){
+                grid[i+k][N-1-i-off+k]=!grid[i+k][N-1-i-off+k];
+                k++;
+            }
+        }
+    }
+    forn(i, N-1){
+        if(!grid[i][i+1])
+            result_offdiag++;
+    }
+
+    ll n_diag = 2 * N - 1 + (N%2);
+    ll n_offdiag = 2 * N - 1 - (N%2);
+    result_diag = min(result_diag, n_diag - result_diag);
+    result_offdiag = min(result_offdiag, n_offdiag - result_offdiag);
+    result = result_diag + result_offdiag;
 }
 
 } // namespace task