View Compilation Error

0_0_14212420_2896.cpp: In function 'void Build()':
0_0_14212420_2896.cpp:21:31: error: 'strlen' was not declared in this scope
     int ind=0,l=strlen(Keyword);
                               ^
0_0_14212420_2896.cpp: In function 'int cal()':
0_0_14212420_2896.cpp:60:21: error: 'strlen' was not declared in this scope
     int l=strlen(Str),ind=0,ans=0;
                     ^
0_0_14212420_2896.cpp:64:18: error: 'ind' was not declared in this scope
         while (p[ind].next[Index]==-1 && ind>0) ind=p[ind].fail;
                  ^
0_0_14212420_2896.cpp:65:15: error: 'ind' was not declared in this scope
         if (p[ind].next[Index]!=-1)
               ^
0_0_14212420_2896.cpp:71:17: error: 'ans' was not declared in this scope
                 ans+=p[q].Count;
                 ^
0_0_14212420_2896.cpp:77:12: error: 'ans' was not declared in this scope
     return ans;
            ^