View Compilation Error

0_0_14213069_5204.cpp: In function 'int main()':
0_0_14213069_5204.cpp:20:38: error: 'strcmp' was not declared in this scope
         if( n==0 && !strcmp(key,"end") )
                                      ^
0_0_14213069_5204.cpp:22:25: error: 'strlen' was not declared in this scope
         lenth=strlen(key);
                         ^