View Compilation Error

0_0_30211022_17502.cpp: In function 'void merge_sort(int, int)':
0_0_30211022_17502.cpp:25:19: error: 'tmp' was not declared in this scope
     while(i <= m) tmp[k++] = a[i++];
                   ^
0_0_30211022_17502.cpp:26:19: error: 'tmp' was not declared in this scope
     while(j <= r) tmp[k++] = a[j++];
                   ^
0_0_30211022_17502.cpp:27:32: error: 'tmp' was not declared in this scope
     for(int i=l;i<=r;i++) a[i]=tmp[i];
                                ^