binperm.cpp:5:17: omp.h: No such file or directory binperm.cpp: In function `void mergeSort(int, int)': binperm.cpp:19: `omp_get_num_threads' undeclared (first use this function) binperm.cpp:19: (Each undeclared identifier is reported only once for each function it appears in.) binperm.cpp:22: warning: ignoring #pragma omp parallel binperm.cpp:25: warning: ignoring #pragma omp sections binperm.cpp:28: warning: ignoring #pragma omp section binperm.cpp:33: warning: ignoring #pragma omp section binperm.cpp:19: warning: unused variable `int nr_threads' binperm.cpp: In function `int main()': binperm.cpp:68: `omp_set_nested' undeclared (first use this function)