View Compilation Error

0_0_20955339_2414.cpp: In function 'int main()':
0_0_20955339_2414.cpp:7:28: error: 'strcmp' was not declared in this scope
             if(strcmp(s,"0")==0)   break;  
                            ^
0_0_20955339_2414.cpp:8:25: error: 'strlen' was not declared in this scope
         int len=strlen(s);    
                         ^