View Compilation Error

0_0_36397452_26924.cpp:4:8: error: 'i' was not declared in this scope
 char s[i];
        ^
0_0_36397452_26924.cpp: In function 'int main()':
0_0_36397452_26924.cpp:9:20: error: 's' was not declared in this scope
         scanf("%s",s+1);
                    ^
0_0_36397452_26924.cpp:11:24: error: 'n' was not declared in this scope
         for(int i=1;i<=n;i++){
                        ^