C++

1 class Solution { 2 public: 3     /** 4      * @param n the nth 5      * @return the nth sequence 6      */ 7     string countAndSay(int n) { 8         // Write your code here 9         if (0 == n) {10             return "";11         }12         string pre = "1";13         for (int i = 1; i < n; i++) {//从第2个（i=1）开始14             char ch = pre[0];15             string cur = "";16             int cnt = 0;17             for (int j = 0; j < pre.size(); j++) {18                 if (pre[j] == ch) {19                     cnt ++;20                 } else {21                     cur = cur + itostr(cnt) + ch;22                     ch = pre[j];23                     cnt = 1;24                 }25             }26             if (cnt != 0) {//处理后边的字符27                 cur = cur + itostr(cnt) + ch;28             }29             pre = cur;30             cur = "";31         }32         return pre;33         34     }35     string itostr(int i) {//自定义int转string函数36         char str[10];37         //itoa(str,i,10);->only support Windows38         sprintf(str, "%d", i);//support any platforms39         return str;40     }41 };