View Compilation Error

0_0_16771485_11349.cpp: In function 'void insertHash(char*, char*)':
0_0_16771485_11349.cpp:46:32: error: 'strcpy' was not declared in this scope
     strcpy(nodeA[curA].que, que);  
                                ^
0_0_16771485_11349.cpp: In function 'int searchHashA(char*)':
0_0_16771485_11349.cpp:65:40: error: 'strcmp' was not declared in this scope
         if (strcmp(que, nodeA[next].que) == 0) return next;  
                                        ^
0_0_16771485_11349.cpp: In function 'int searchHashB(char*)':
0_0_16771485_11349.cpp:77:40: error: 'strcmp' was not declared in this scope
         if (strcmp(ans, nodeA[next].ans) == 0) return next;  
                                        ^
0_0_16771485_11349.cpp: In function 'int main()':
0_0_16771485_11349.cpp:112:30: error: 'strlen' was not declared in this scope
             qlen = strlen(str);  
                              ^
0_0_16771485_11349.cpp:120:30: error: 'strlen' was not declared in this scope
             alen = strlen(str);  
                              ^