随笔- 509  文章- 0  评论- 151  阅读- 22万 

Isomorphic Strings

2015.4.30 15:54

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

For example,
Given "egg""add", return true.

Given "foo""bar", return false.

Given "paper""title", return true.

Note:
You may assume both s and t have the same length.

Solution:

  Think about the string pair "abb" and "cdd". An isomorphic pair is like one-to-one mapping. So we use the basic priniciple: injective + surjective = bijective.

  Check if the mapping from s to t is onto, and t to s as well. If both hold, they're isomorphic.

Accepted code:

复制代码
 1 #include <cstring>
 2 using namespace std;
 3 
 4 class Solution {
 5 public:
 6     bool isIsomorphic(string s, string t) {
 7         return check(s, t) && check(t, s);
 8     }
 9 private:
10     bool check(string s, string t) {
11         char a[256];
12         
13         memset(a, 0, sizeof(a));
14         int i;
15         int n = s.length();
16         
17         for (i = 0; i < n; ++i) {
18             if (a[s[i]] == 0) {
19                 a[s[i]] = t[i];
20             }
21             s[i] = a[s[i]];
22         }
23         
24         return s == t;
25     }
26 };
复制代码

 

 posted on   zhuli19901106  阅读(278)  评论(0编辑  收藏  举报
编辑推荐:
· 一个奇形怪状的面试题:Bean中的CHM要不要加volatile?
· [.NET]调用本地 Deepseek 模型
· 一个费力不讨好的项目,让我损失了近一半的绩效!
· .NET Core 托管堆内存泄露/CPU异常的常见思路
· PostgreSQL 和 SQL Server 在统计信息维护中的关键差异
阅读排行:
· DeepSeek “源神”启动!「GitHub 热点速览」
· 我与微信审核的“相爱相杀”看个人小程序副业
· 微软正式发布.NET 10 Preview 1:开启下一代开发框架新篇章
· 如何使用 Uni-app 实现视频聊天(源码,支持安卓、iOS)
· C# 集成 DeepSeek 模型实现 AI 私有化(本地部署与 API 调用教程)
历史上的今天:
2014-04-30 Careercup - Facebook面试题 - 5110993575215104
点击右上角即可分享
微信分享提示