From 0dfe4ed7338f255076da009e8ae974ca3d76ea2e Mon Sep 17 00:00:00 2001
From: Powfu <1875065753@qq.com>
Date: Tue, 26 Dec 2023 13:06:17 +0000
Subject: [PATCH] =?UTF-8?q?add=202101040022/chapter=5F5/=E6=81=A2=E5=A4=8D?=
 =?UTF-8?q?IP=E5=9C=B0=E5=9D=80.cpp.?=
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Signed-off-by: Powfu <1875065753@qq.com>
---
 ...345\244\215IP\345\234\260\345\235\200.cpp" | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 "2101040022/chapter_5/\346\201\242\345\244\215IP\345\234\260\345\235\200.cpp"

diff --git "a/2101040022/chapter_5/\346\201\242\345\244\215IP\345\234\260\345\235\200.cpp" "b/2101040022/chapter_5/\346\201\242\345\244\215IP\345\234\260\345\235\200.cpp"
new file mode 100644
index 00000000..14e42577
--- /dev/null
+++ "b/2101040022/chapter_5/\346\201\242\345\244\215IP\345\234\260\345\235\200.cpp"
@@ -0,0 +1,54 @@
+#include<stdio.h>
+using namespace std;
+class Solution {
+public:
+	vector<string> res;
+	vector<string> restoreIpAddresses(string s) {
+		if (s.size() > 12)
+			return res;
+		//cur为当前分割的一种情况，pos当前s下标，cnt计数
+		string cur;
+		Recursion(s, cur, 0, 0);
+		return res;
+	}
+	void Recursion(string &s, string cur, int pos, int cnt)
+	{
+		if (pos == s.size())
+		{
+			//当pos到尾且cnt=4，则是正确分割，否则返回
+			if (cnt == 4)
+			{
+				cur.pop_back();
+				res.push_back(cur);
+			}	
+			return;
+		}
+		//Ip地址每一部分可能是一位数0-9
+		cur += s.substr(pos, 1) + '.';
+		Recursion(s, cur, pos + 1, cnt + 1);
+		cur.erase(cur.size() - 2, 2);
+		//Ip地址每一部分可能是两位数10-99
+		if (pos + 1 < s.size() && s[pos] != '0')
+		{
+			cur += s.substr(pos, 2) + '.';
+			Recursion(s, cur, pos + 2, cnt + 1);
+			cur.erase(cur.size() - 3, 3);
+		}
+		//Ip地址每一部分可能是三位数100-255
+		if (pos + 2 < s.size() && (s[pos] == '1'|| (s[pos]=='2' && s.substr(pos,3)<="255")))
+		{
+			cur += s.substr(pos, 3) + '.';
+			Recursion(s, cur, pos + 3, cnt + 1);
+			cur.erase(cur.size() - 4, 4);
+		}
+		return;
+	}
+};
+int main()
+{
+	Solution solute;
+	string s = "172162541";
+	vector<string> res = solute.restoreIpAddresses(s);
+	copy(res.begin(), res.end(), ostream_iterator<string>(cout, "\n"));
+	return 0;
+}
\ No newline at end of file
-- 
Gitee