"Restore IP Addresses"

Author: lennylxx

README.md

@@ -195,7 +195,7 @@ The `☢` means that you need to have a LeetCode Premium Subscription.
 | 96  | [Unique Binary Search Trees]                                 | [C](src/96.c)      |
 | 95  | [Unique Binary Search Trees II]                              | [C++](src/95.cpp)  |
 | 94  | [Binary Tree Inorder Traversal]                              | [C](src/94.c)      |
-| 93  | [Restore IP Addresses]                                       |                    |
+| 93  | [Restore IP Addresses]                                       | [C++](src/93.cpp)  |
 | 92  | [Reverse Linked List II]                                     | [C](src/92.c)      |
 | 91  | [Decode Ways]                                                | [C](src/91.c)      |
 | 90  | [Subsets II]                                                 |                    |

src/93.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+  public:
+    vector<string> restoreIpAddresses(string s) {
+        vector<string> temp;
+        vector<string> ans;
+
+        dfs(s, temp, ans);
+
+        return ans;
+    }
+
+    void dfs(string s, vector<string> &temp, vector<string> &ans) {
+        if (temp.size() == 4 && s.length() == 0) {
+            ans.push_back(temp[0] + "." + temp[1] + "." + temp[2] + "." + temp[3]);
+            return;
+        }
+        else if (temp.size() >= 4) {
+            return;
+        }
+
+        for(int i = 1; i <= 3 && i <= s.length(); i++) {
+            string t = s.substr(0, i);
+            if (t.length() > 1 && t[0] == '0') break;
+            if (stoi(t) > 255) break;
+            temp.push_back(t);
+            dfs(s.substr(i, s.length() - i), temp, ans);
+            temp.pop_back();
+        }
+    }
+};
+
+int main() {
+    string str = "010010";
+    Solution s;
+    vector<string> ret = s.restoreIpAddresses(str);
+
+    for (int i = 0; i < ret.size(); i++) {
+        cout << ret[i] << endl;
+    }
+    return 0;
+}