View Compilation Error

0_0_17250071_11906.cpp: In function 'void createTrie(char*)':
0_0_17250071_11906.cpp:13:25: error: 'strlen' was not declared in this scope
     int len = strlen(str);
                         ^
0_0_17250071_11906.cpp: In function 'int findTrie(char*)':
0_0_17250071_11906.cpp:37:25: error: 'strlen' was not declared in this scope
     int len = strlen(str);
                         ^
0_0_17250071_11906.cpp: In function 'int main()':
0_0_17250071_11906.cpp:58:31: error: 'memset' was not declared in this scope
     memset(str, 0, sizeof(str));
                               ^