From ccc1995cb89107e7c8ba5795346f93ea16a959e7 Mon Sep 17 00:00:00 2001
From: hladu357 <ondrej.hladuvka@gmail.com>
Date: Sat, 18 May 2024 13:27:21 +0200
Subject: [PATCH] lock

---
 lock.cpp | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 lock.cpp

diff --git a/lock.cpp b/lock.cpp
new file mode 100644
index 0000000..f2dc7a2
--- /dev/null
+++ b/lock.cpp
@@ -0,0 +1,72 @@
+#include <vector>
+#include <unordered_set>
+#include <string>
+#include <queue>
+#include <iostream>
+
+class Solution {
+public:
+    union u {
+        public:
+        char c[4];
+        int i;
+    };
+
+    int openLock(std::vector<std::string>& deadends, std::string target) {
+        std::unordered_set<int> e;
+        std::queue<std::pair<u,int>> q;
+
+        u t;
+        u b;
+        b.i = 0;
+        for (int i = 0; i < 4; ++i) {
+            t.c[i] = static_cast<char>(target[i] - '0');
+        }
+        for (const auto& i : deadends) {
+            if (target == i || target == "0000") return -1;
+
+            u tmp;
+            for (int j = 0; j < 4; ++j) {
+                tmp.c[j] = static_cast<char>(i[j] - '0');
+            }
+            e.insert(tmp.i);
+        }
+
+        
+
+        e.insert(0);
+        q.emplace(b,0);
+
+        while(q.size()) {
+            auto i = q.front();
+            q.pop();
+            if (i.first.i == t.i) return i.second;
+
+            for (int j = 0; j < 4; ++j) {
+                u w = i.first;
+                ++w.c[j] %= 10;                
+                auto it = e.emplace(w.i);
+                if (it.second) {
+                    q.emplace(w, i.second + 1);
+                }
+            }
+
+            for (int j = 0; j < 4; ++j) {
+                u w = i.first;
+                if (!w.c[j]--) w.c[j] = 9;                
+                auto it = e.emplace(w.i);
+                if (it.second) {
+                    q.emplace(w, i.second + 1);
+                }
+            }
+        }
+        return -1;
+    }
+};
+
+int main() {
+    Solution s;
+    std::vector<std::string> v = {"8888"};
+    std::cout << s.openLock(v, "0009");
+    return 0;
+}
\ No newline at end of file