View Compilation Error

0_0_38080401_27115.cpp: In function 'int main()':
0_0_38080401_27115.cpp:61:18: error: 'n' was not declared in this scope
         x[a++] = n;
                  ^
0_0_38080401_27115.cpp:71:22: error: 'sort' was not declared in this scope
         sort(x, x + a);
                      ^
0_0_38080401_27115.cpp:72:28: error: 'unique' was not declared in this scope
         a = unique(x, x + a) - x;
                            ^
0_0_38080401_27115.cpp:113:31: error: 'memset' was not declared in this scope
         memset(g, 0, sizeof(g));
                               ^