View Compilation Error

0_0_36750518_5912.cpp: In function 'int main()':
0_0_36750518_5912.cpp:139:5: error: redefinition of 'int main()'
 int main() {
     ^
0_0_36750518_5912.cpp:94:5: note: 'int main()' previously defined here
 int main() {
     ^
0_0_36750518_5912.cpp:143:16: error: 'tree' was not declared in this scope
         cin >> tree[0][i];
                ^
0_0_36750518_5912.cpp:144:9: error: 'sorted' was not declared in this scope
         sorted[i] = tree[0][i];
         ^
0_0_36750518_5912.cpp:146:10: error: 'sorted' was not declared in this scope
     sort(sorted + 1, sorted + n + 1);
          ^
0_0_36750518_5912.cpp:147:23: error: 'Build_tree' was not declared in this scope
     Build_tree(0, 1, n);
                       ^
0_0_36750518_5912.cpp:151:43: error: 'Query' was not declared in this scope
         int ans = Query(0, ql, qr, 1, n, k);
                                           ^