From e944bd3cbb994f330ba9f3004720e10de42b28a7 Mon Sep 17 00:00:00 2001
From: daviddoji <daviddoji@pm.me>
Date: Mon, 6 Sep 2021 20:25:53 +0200
Subject: [PATCH] Module 17: Write Words to the Grid

---
 a.c | 80 ++++++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 55 insertions(+), 25 deletions(-)

diff --git a/a.c b/a.c
index b6b0e26..82977d5 100644
--- a/a.c
+++ b/a.c
@@ -8,6 +8,8 @@ using namespace std;
 
 // For compiling C++ code
 // g++ a.c -o a
+// with optimizations
+// g++ a.c -O2 -o a
 
 string ToUpper(string s) {
   string s2;
@@ -139,14 +141,13 @@ public:
     while (f.is_open() && !f.eof()) {  // check for the file!
       string line;
       getline(f, line);
-      // cout << line << "\n";
       if (!line.empty()) {
         line = ToUpper(line);
         int len = line.length();
         if (line[len - 1] == '\r') {
           line = line.substr(0, len - 1);
         }
-        if (len <= max_size) {
+        if (line.length() <= max_size) {
           Word* w = new Word(line);
           words_.push_back(w);  // Word would be allocated on the heap
           CreatePatternHash(w);
@@ -202,6 +203,10 @@ struct Grid {
     assert(in_bounds(p));
     return lines[p.row][p.col];
   }
+  void write_box(const Point& p, char c) {
+    assert(in_bounds(p));
+    lines[p.row][p.col] = c;
+  }
   // Returns true if point p is a '.' "block" in the grid
   // 'p' must be in bounds
   bool is_block(const Point& p) const {
@@ -234,6 +239,14 @@ struct Grid {
     }
     return temp; 
   }
+  void WriteString(const Span& s, const string& t) {
+    int len = s.len;
+    assert(t.length() == len);
+    for (int i=0; i<len; i++) {
+      Point p = s.GetPoint(i);
+      write_box(p, t[i]);
+    }    
+  }
   // Next increments the point across the grid, one box at a time
   // Returns true if point is still in bounds
   bool Next(Point& p, bool vert) {
@@ -359,21 +372,26 @@ ostream& operator<<(ostream& os, const Slot& s) {
 //-Solver
 class Solver {
   public:
-    Solver(Grid* g) : grid_(g) {}  // pointer to the grid
-    void Solve() {
+    Solver() {}
+    void Solve(const Grid& grid) {  // reference to the grid
       cout << "Solving this grid:\n";
-      grid_->Print();  
-      Loop();
+      grid.Print();  
+      Loop(grid, 0);
     }
 
   private:
-    void Loop() {
+    void Loop(Grid grid, int depth) { // full copy of the grid to allow recursion
+      depth++;
+      // if (depth > 3) {
+      //   cout << "Aborting loop because depth=" << depth << "\n";
+      //   return;
+      // }
       Slots empty_slots;  // these are the ones we want to work on
       Slots partial_slots;
       Slots full_slots;  
-      for (const Span& s : grid_->spans) {
+      for (const Span& s : grid.spans) {
         Attr attr;
-        string temp = grid_->GetString(s, attr);
+        string temp = grid.GetString(s, attr);
         if (attr.is_empty()) {
           empty_slots.push_back(Slot(s, temp));
         } else if (attr.is_partial()) {
@@ -385,31 +403,43 @@ class Solver {
       int num_empty = empty_slots.size();
       int num_partial = partial_slots.size();
       int num_full = full_slots.size();
-      cout << "empty = " << num_empty << "\n";
-      cout << "partial = " << num_partial << "\n";
-      cout << "full = " << num_full << "\n";
+      // cout << "empty = " << num_empty << "\n";
+      // cout << "partial = " << num_partial << "\n";
+      // cout << "full = " << num_full << "\n";
+
+      // need to check that all words so far are valid!
+      for (const Slot& s : full_slots) {
+        // cout << "CHECKING " << s.pattern << " if it is a word\n";
+        if (!lib.IsWord(s.pattern)) {
+          // cout << "  --> NOT! ABORT\n";
+          return;
+        }
+      }
       if (num_partial == 0 && num_empty == 0) {
         cout << "SOLUTION!!\n";
-        // FIX what do we do here?
+        grid.Print();
+        return;
       }
       assert(num_partial > 0);
-      CommitSlot(partial_slots[0]);
+      CommitSlot(grid, partial_slots[0], depth);
     }
-    void CommitSlot(const Slot& slot) {
-      cout << "COMMIT slot " << slot << "\n";
-      cout << "Possible word choices for this slot are:\n";
+    void CommitSlot(Grid& grid, const Slot& slot, int depth) {
+      // cout << "COMMIT slot " << slot << "\n";
+      // cout << "Possible word choices for this slot are:\n";
 
       const Words* words = lib.FindWord(slot.pattern);
       if (words) {
         for (const Word* w : *words) {
-          cout << " " << w->word;
-        }
-        cout << "\n";
-        } else {
-          cout << "NO MATCHES to pattern\n";
+          // cout << "  Committing '" << w->word << "'!\n";
+          grid.WriteString(slot.span, w->word);
+          // cout << "New grid is:\n";
+          // grid.Print();
+          Loop(grid, depth);  // Recursion
         }
+      } else {
+        // cout << "NO MATCHES to pattern\n";
+      }
     }
-    Grid* grid_;
 };
 
 // --------------------------------------------------------------------------------
@@ -422,6 +452,6 @@ int main() {
 
   lib.ReadFromFile("top_12000.txt", grid.max_size());
 
-  Solver solver(&grid);  // address pointer to the grid
-  solver.Solve();
+  Solver solver;
+  solver.Solve(grid);
 }
\ No newline at end of file