View Compilation Error

0_0_18907103_29087.cpp: In function 'int main()':
0_0_18907103_29087.cpp:19:27: error: 'memset' was not declared in this scope
   memset(dp, 0, sizeof(dp));
                           ^
0_0_18907103_29087.cpp:21:25: error: 'strlen' was not declared in this scope
   int len = strlen(str+1);
                         ^