View Compilation Error

0_0_36070488_11205.cpp: In function 'void build(int, int, int)':
0_0_36070488_11205.cpp:21:16: error: return-statement with a value, in function returning 'void' [-fpermissive]
         return 0;
                ^
0_0_36070488_11205.cpp: In function 'int main()':
0_0_36070488_11205.cpp:58:21: error: 'n' was not declared in this scope
         scanf("%d",&n);
                     ^
0_0_36070488_11205.cpp:80:13: error: expected ';' before '{' token
             {
             ^