Q. What do you mean by Single Construct in FORTAN?

Single construct specifies the associated structured block is executed by just one thread in team (not essentially the master thread). The other threads in team don't execute the block and wait at an implicit barrier at end of single construct except a nowait clause is specified. The syntax of single construct is as below:

#pragma omp single [set of clauses]

structured-block

 The clause is one of the following:

private(list)

firstprivate(list)

copyprivate(list)

nowait