LintCode: Count and Say

C++

 class Solution {
 public:
     /**
      * @param n the nth
      * @return the nth sequence
      */
     string countAndSay(int n) {
         // Write your code here
         if ( == n) {
             return "";
         }
         string pre = "";
         for (int i = ; i < n; i++) {//从第2个（i=1）开始
             char ch = pre[];
             string cur = "";
             int cnt = ;
             for (int j = ; j < pre.size(); j++) {
                 if (pre[j] == ch) {
                     cnt ++;
                 } else {
                     cur = cur + itostr(cnt) + ch;
                     ch = pre[j];
                     cnt = ;
                 }
             }
             if (cnt != ) {//处理后边的字符
                 cur = cur + itostr(cnt) + ch;
             }
             pre = cur;
             cur = "";
         }
         return pre;

     }
     string itostr(int i) {//自定义int转string函数
         char str[];
         //itoa(str,i,10);->only support Windows
         sprintf(str, "%d", i);//support any platforms
         return str;
     }
 };