压缩字符串 （3.16 leetcode每日打卡）

 1 char* compressString(char* S)
 2 {
 3     int i, len;
 4     int cnt = 1;
 5     int j = -1;
 6         char dealS[500000];
 7     memset(dealS, ‘0‘, 500000);
 8 
 9     char ch = S[0];
10     for (i = 0; S[i]; i++);  //测量长度 其实可以用strlen
11     len = i;
12     if (len == 1)
13     return S;
14     for (i = 1; i < len+1; i++)  //len+1是为了防止还没等压缩就因为到了末尾而跳出遍历了了
15     {
16         if (ch == S[i])
17         {
18             cnt++;
19         }
20         else
21         {
22             dealS[++j] = ch;
23             if (cnt < 10) //判断计数器大于还是小于0
24             {
25                 dealS[++j] = (char)(cnt + 48);
26             }
27             else
28             {
29                 char buffer[25];
30                 sprintf(buffer, "%d", cnt);
31                 for (int k = 0; buffer[k]; k++)
32                 {
33                     dealS[++j] = buffer[k];
34                 }
35             }
36 
37             ch = S[i];
38             i--;
39             cnt = 0;
40         }
41     }
42 
43     dealS[++j] = ‘\0‘;
44     return strlen(dealS) < strlen(S) ? dealS : S;
45 }