View Compilation Error

0_0_25410159_18036.cpp: In function 'int main()':
0_0_25410159_18036.cpp:13:18: error: 'strlen' was not declared in this scope
   length=strlen(a);
                  ^
0_0_25410159_18036.cpp:14:15: error: expected unqualified-id before 'int'
   for(int i=0,int j=0;i<length;i++)
               ^
0_0_25410159_18036.cpp:14:15: error: expected ';' before 'int'
0_0_25410159_18036.cpp:14:31: error: expected ')' before ';' token
   for(int i=0,int j=0;i<length;i++)
                               ^
0_0_25410159_18036.cpp:14:32: error: 'i' was not declared in this scope
   for(int i=0,int j=0;i<length;i++)
                                ^
0_0_25410159_18036.cpp:19:9: error: 'j' was not declared in this scope
   cout<<j<<endl;
         ^