View Compilation Error

0_0_19821876_8908.cpp: In function 'int findWordsInTitle(char*, int, int, int)':
0_0_19821876_8908.cpp:62:51: error: 'strcpy' was not declared in this scope
                 strcpy(art[num].words[k++], tmpstr);
                                                   ^
0_0_19821876_8908.cpp:66:53: error: 'strcpy' was not declared in this scope
                 strcpy(queryWords.words[k++] ,tmpstr);
                                                     ^
0_0_19821876_8908.cpp: In function 'int compareTwoTitles(Node, Node)':
0_0_19821876_8908.cpp:95:54: error: 'strcmp' was not declared in this scope
             if (!strcmp(word.words[i], title.words[j]))
                                                      ^
0_0_19821876_8908.cpp: In function 'int main()':
0_0_19821876_8908.cpp:125:36: error: 'memset' was not declared in this scope
         memset(&art, 0, sizeof(art));
                                    ^
0_0_19821876_8908.cpp:132:37: error: 'strlen' was not declared in this scope
             n = strlen(art[i].oldStr);
                                     ^