View Compilation Error

0_0_19582400_17291.cpp: In function 'int kmp(char*, char*, int*)':
0_0_19582400_17291.cpp:20:22: error: 'strlen' was not declared in this scope
     int lenp=strlen(p);
                      ^
0_0_19582400_17291.cpp: In function 'int main()':
0_0_19582400_17291.cpp:42:38: error: 'strcmp' was not declared in this scope
     while(scanf("%s",a)&&strcmp(a,"#")!=0)
                                      ^
0_0_19582400_17291.cpp:46:60: error: 'strlen' was not declared in this scope
                                            int len=strlen(b);
                                                            ^
0_0_19582400_17291.cpp:48:70: error: 'memset' was not declared in this scope
                                            memset(next,0,sizeof(next));
                                                                      ^