View Compilation Error

0_0_17437580_333.cpp:3:1: error: 'usingnamespace' does not name a type
 usingnamespace std;
 ^
0_0_17437580_333.cpp: In function 'void Tarjan(int)':
0_0_17437580_333.cpp:36:23: error: 'elseif' was not declared in this scope
         }elseif(ins[v]){
                       ^