View Compilation Error

0_0_36695331_19368.cpp: In function 'int main()':
0_0_36695331_19368.cpp:30:7: error: missing template arguments before 'st'
 stack st[105];  
       ^
0_0_36695331_19368.cpp:31:21: error: 'st' was not declared in this scope
 for(int i=0;i<n;i++)st[i].push(i); 
                     ^
0_0_36695331_19368.cpp:37:8: error: 'st' was not declared in this scope
 while(!st[l-1].empty()){
        ^
0_0_36695331_19368.cpp:44:8: error: 'st' was not declared in this scope
 while(!st[r+1].empty()){  
        ^
0_0_36695331_19368.cpp:50:28: error: 'st' was not declared in this scope
 for(int i=0;i<n;i++){ar[i]=st[l].top();st[l].pop();}
                            ^