View Compilation Error

0_0_24129038_6219.cpp: In function 'int main()':
0_0_24129038_6219.cpp:22:9: error: 'unordered_map' was not declared in this scope
         unordered_map<int,int> m1;
         ^
0_0_24129038_6219.cpp:22:23: error: expected primary-expression before 'int'
         unordered_map<int,int> m1;
                       ^
0_0_24129038_6219.cpp:32:9: error: 'm1' was not declared in this scope
         m1[a1[0]]=++n1;
         ^
0_0_24129038_6219.cpp:49:28: error: 'ya' was not declared in this scope
                 if(d[xa+j][ya]==1&&d[xa][ya+j]==1&&d[xa+j][ya+j]==1)
                            ^