View Compilation Error

0_0_20004049_15715.cpp: In function 'int main()':
0_0_20004049_15715.cpp:14:23: error: 'memset' was not declared in this scope
   memset(a,1,sizeof(a));
                       ^
0_0_20004049_15715.cpp:20:27: error: 'strcpy' was not declared in this scope
     strcpy(Arraystr[0],str);
                           ^
0_0_20004049_15715.cpp:25:34: error: 'strcmp' was not declared in this scope
         if(strcmp(Arraystr[j],str)==0)
                                  ^
0_0_20004049_15715.cpp:31:34: error: 'strcpy' was not declared in this scope
          strcpy(Arraystr[k++],str);
                                  ^