View Compilation Error

0_0_22128880_1401.cpp: In function 'int main()':
0_0_22128880_1401.cpp:68:39: error: 'memset' was not declared in this scope
         memset(result,0,sizeof(result));
                                       ^
0_0_22128880_1401.cpp:118:46: error: 'strlen' was not declared in this scope
         int len=(result[0]-1)*9+strlen(assist);
                                              ^