Create str.cpp

Author: wlgq2

0____剑指offer/other/38/str.cpp

@@ -0,0 +1,38 @@
+class Solution
+{
+public:
+    void permutation(string& str, string& temp,vector<string>& strs)
+    {
+        auto index = temp.size();
+        if (index == str.size())
+        {
+            strs.push_back(temp);
+            return;
+        }
+        std::set<int> cache;
+        for (int i = index;i <str.size(); i++)
+        {
+            auto ch = str[i];
+            if (cache.find(ch) == cache.end())
+            {
+                cache.insert(ch);
+                temp.push_back(ch);
+                str[i] = str[index];
+                str[index] = ch;
+                permutation(str, temp, strs);
+                str[index] = str[i];
+                str[i] = ch;
+                temp.pop_back();
+            }
+        }
+    }
+    vector<string> permutation(string s)
+    {
+        vector<string> rst;
+        string temp;
+        temp.resize(s.size());
+        temp.clear();
+        permutation(s, temp, rst);
+        return rst;
+    }
+};