From 7b3aa9c871ff1f6c659504aa8bbc162ec4696e09 Mon Sep 17 00:00:00 2001
From: Daniel Ledda <daniel.ledda@stock3.com>
Date: Sat, 19 Nov 2022 15:57:19 +0100
Subject: [PATCH] added old backtrack algo

---
 main.cpp | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/main.cpp b/main.cpp
index 68bb929..c4bb4f9 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,9 +1,11 @@
+#include <bitset>
 #include <iostream>
 #include <string>
+#include <algorithm>
 #include <vector>
 #include "VoxelSpace.h"
 
-auto backtrack_solve(std::vector<uint64_t> *polycube_input, std::vector<int> *offsets)-> void {
+auto backtrack_solve_iter(std::vector<uint64_t> *polycube_input, std::vector<int> *offsets)-> void {
     auto num_inputs = offsets->size() - 1;
 
     auto solns = std::vector<int>();
@@ -51,6 +53,25 @@ auto backtrack_solve(std::vector<uint64_t> *polycube_input, std::vector<int> *of
     std::cout << "Done. Found " << solns.size() << " solutions." << std::endl;
 }
 
+auto backtrack_solve(std::vector<uint64_t> *polycube_input, std::vector<int> *offsets, uint64_t working_solution = 0ull, int set = 0) -> int {
+    auto solns = 0;
+    auto start = offsets->at(set);
+    auto end = offsets->at(set + 1);
+    std::cout << start << " " << end << "\n"; 
+    for (int i = start; i < end; i++) {
+        auto successful_fuse = (working_solution | polycube_input->at(i)) == (working_solution ^ polycube_input->at(i));
+        if (successful_fuse) {
+            working_solution = working_solution | polycube_input->at(i);
+            if (set == offsets->size() - 2) {
+                return solns + 1;
+            } else {
+                solns += backtrack_solve(polycube_input, offsets, working_solution, set + 1);
+            }
+        }
+    }
+    return solns;
+}
+
 auto get_dims_input(int dims[3]) -> void {
     std::cout << "Enter dimensions separated by newlines. (x*y*z must not exceed 64)\n";
     auto success = false;
@@ -109,8 +130,8 @@ auto get_reprs_input(int units_required) -> std::vector<uint64_t> {
 }
 
 auto main() -> int {
-    int dims[3] = {};
-    get_dims_input(dims);
+    int dims[3] = { 3, 3, 3 };
+    //get_dims_input(dims);
     std::cout << '\n';
     //auto reprs = get_reprs_input(dims[0]*dims[1]*dims[2]);
     auto reprs = std::vector<uint64_t>{
@@ -137,7 +158,6 @@ auto main() -> int {
     auto space = model_space;
     space.space = reprs[0];
     Voxel::cullEmptySpace(&space);
-        std::cout << space.dims[0] << space.dims[1] << space.dims[2] << std::endl;
     auto positions = Voxel::getUniqueRotations(&space);
     polycubes.insert(polycubes.end(), positions.begin(), positions.end());
 
@@ -146,13 +166,17 @@ auto main() -> int {
         auto space = model_space;
         space.space = reprs[i];
         Voxel::cullEmptySpace(&space);
-        std::cout << space.dims[0] << space.dims[1] << space.dims[2] << std::endl;
         auto perms = Voxel::getUniqueRotations(&space);
         polycubes.insert(polycubes.end(), perms.begin(), perms.end());
     }
 
     offsets.push_back(polycubes.size());
 
-    //backtrack_solve(&polycubes, &offsets);
+    auto spaces = std::vector<uint64_t>(polycubes.size());
+    std::transform(polycubes.begin(), polycubes.end(), spaces.begin(), [](auto i) { return i.space; });
+
+    auto solns = backtrack_solve(&spaces, &offsets);
+
+    std::cout << solns << std::endl;
     return 0;
 }