【leetcode】【easy】【每日一题】面试题 01.06. Compress String LCCI

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本文深入解析了一种基本的字符串压缩算法，该算法通过计算字符重复次数进行压缩。以aabcccccaaa为例，压缩后的结果为a2b1c5a3。文章详细介绍了算法的实现思路及代码实现，同时提供了LeetCode上的题目链接，帮助读者更好地理解和掌握字符串压缩的方法。

面试题 01.06. Compress String LCCI

Implement a method to perform basic string compression using the counts of repeated characters. For example, the string aabcccccaaa would become a2blc5a3. If the "compressed" string would not become smaller than the original string, your method should return the original string. You can assume the string has only uppercase and lowercase letters (a - z).

Example 1:

Input: "aabcccccaaa"
Output: "a2b1c5a3"

Example 2:

Input: "abbccd"
Output: "abbccd"
Explanation: 
The compressed string is "a1b2c2d1", which is longer than the original string.

Note:

0 <= S.length <= 50000

题目链接：https://leetcode-cn.com/problems/compress-string-lcci/

思路

非常简单的题，模拟机器处理过程，一步一步做即可。

class Solution {
public:
    string compressString(string S) {
        int len = S.size();
        if(len==0) return S;
        string res = "";
        int cnt = 1;
        char ch = S[0];
        for(int i=1; i<len; ++i){
            if(S[i]==ch){
                ++cnt;
            }else{
                res += ( ch + to_string(cnt));
                ch = S[i];
                cnt = 1;
            }
        }
        res += (ch + to_string(cnt));
        return (res.size()<len)?res:S;
    }
};