Add problem 213 .

1 files changed, 41 insertions, 0 deletions

diff --git a/cpp/213.cpp b/cpp/213.cpp
new file mode 100644
index 0000000..1414222
--- /dev/null
+++ b/cpp/213.cpp
@@ -0,0 +1,41 @@
+#include <vector>
+
+using std::vector;
+
+class Solution
+{
+public:
+    int rob(vector<int> &nums)
+    {
+        int count = nums.size();
+        if (count == 0)
+            return 0;
+
+        if (count == 1)
+            return nums.front();
+
+        int not_rob_prev = 0;
+        int rob_prev = nums.front();
+        int not_rob_prev_and_not_rob_first = 0;
+        int rob_prev_and_not_rob_first = 0;
+
+        for (int i = 1; i < count - 1; i++)
+        {
+            int not_rob_prev_cache = not_rob_prev;
+            int not_rob_prev_and_not_rob_first_cache = not_rob_prev_and_not_rob_first;
+            not_rob_prev = std::max(not_rob_prev_cache, rob_prev);
+            rob_prev = std::max(not_rob_prev_cache + nums[i], not_rob_prev);
+            not_rob_prev_and_not_rob_first = std::max(not_rob_prev_and_not_rob_first_cache, rob_prev_and_not_rob_first);
+            rob_prev_and_not_rob_first = std::max(not_rob_prev_and_not_rob_first_cache + nums[i], not_rob_prev_and_not_rob_first);
+        }
+
+        // last houst
+        {
+            int not_rob_prev_and_not_rob_first_cache = not_rob_prev_and_not_rob_first;
+            not_rob_prev_and_not_rob_first = std::max(not_rob_prev_and_not_rob_first_cache, rob_prev_and_not_rob_first);
+            rob_prev_and_not_rob_first = std::max(not_rob_prev_and_not_rob_first_cache + nums[count - 1], not_rob_prev_and_not_rob_first);
+        }
+
+        return std::max(rob_prev, rob_prev_and_not_rob_first);
+    }
+};