View Compilation Error

0_0_33940868_1217.cpp: In function 'int main()':
0_0_33940868_1217.cpp:48:36: error: 'strcmp' was not declared in this scope
            if( s==0&&strcmp(str,"0")==0)
                                    ^
0_0_33940868_1217.cpp:50:26: error: 'strlen' was not declared in this scope
            len=strlen(str);
                          ^
0_0_33940868_1217.cpp:51:36: error: 'memset' was not declared in this scope
            memset(map,0,sizeof(map));
                                    ^