View Compilation Error

0_0_30431854_21535.cpp: In function 'int main()':
0_0_30431854_21535.cpp:66:47: error: 'len' was not declared in this scope
                 printf("%d\n", cycle_len-slen%len);//把循环部分去掉，再用cycle_len减就是需要加上的，如abcab，3-5%3=1
                                               ^