From 4c214298836df78f4c39bc4461163287a7d3c10a Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Wed, 13 May 2020 18:35:51 +0800
Subject: Add problem 77 .

---
 cpp/.gitignore |  4 +++-
 cpp/77.cpp     | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 cpp/77.cpp

(limited to 'cpp')

diff --git a/cpp/.gitignore b/cpp/.gitignore
index adb36c8..d1d85a8 100644
--- a/cpp/.gitignore
+++ b/cpp/.gitignore
@@ -1 +1,3 @@
-*.exe
\ No newline at end of file
+*.exe
+*.pdb
+*.ilk
\ No newline at end of file
diff --git a/cpp/77.cpp b/cpp/77.cpp
new file mode 100644
index 0000000..ec09198
--- /dev/null
+++ b/cpp/77.cpp
@@ -0,0 +1,45 @@
+#include <vector>
+
+using std::vector;
+
+void combine1(int start, int end, int rest_select_count, vector<int> &head, vector<vector<int>> &result)
+{
+    if (rest_select_count == 0)
+    {
+        for (int i = start; i < end; i++)
+        {
+            head.push_back(i);
+            result.push_back(head);
+            head.pop_back();
+        }
+        return;
+    }
+
+    for (int i = start; i < end - rest_select_count; i++)
+    {
+        head.push_back(i);
+        combine1(i + 1, end, rest_select_count - 1, head, result);
+        head.pop_back();
+    }
+}
+
+class Solution
+{
+public:
+    vector<vector<int>> combine(int n, int k)
+    {
+        vector<vector<int>> result;
+
+        vector<int> head;
+        combine1(1, 1 + n, k - 1, head, result);
+
+        return result;
+    }
+};
+
+int main()
+{
+    Solution s;
+    auto result = s.combine(20, 16);
+    return 0;
+}
\ No newline at end of file
-- 
cgit v1.2.3