View Compilation Error

0_0_29886733_9639.cpp: In member function 'int PalindromicTree::newnode(int)':
0_0_29886733_9639.cpp:30:41: error: 'memset' was not declared in this scope
   memset(next[tot], 0, sizeof(next[tot]));
                                         ^
0_0_29886733_9639.cpp: In member function 'void PalindromicTree::init()':
0_0_29886733_9639.cpp:42:27: error: 'memset' was not declared in this scope
   memset(bj, 0, sizeof(bj));
                           ^
0_0_29886733_9639.cpp: In function 'int main()':
0_0_29886733_9639.cpp:78:21: error: 'strlen' was not declared in this scope
   int n = strlen(str);
                     ^