Compilare: main.cpp: In function 'int main()': main.cpp:50:9: warning: unused variable 'val1' [-Wunused-variable] int val1=det_sum_mx(a,n,pi_a,pf_a); ^~~~ main.cpp:51:9: warning: unused variable 'val2' [-Wunused-variable] int val2=det_sum_mx(b,m,pi_b,pf_b); ^~~~ main.cpp:30:7: warning: 'pf_a' may be used uninitialized in this function [-Wmaybe-uninitialized] pf--; ^ main.cpp:49:19: note: 'pf_a' was declared here int pi_a,pi_b,pf_a,pf_b; ^~~~ main.cpp:67:35: warning: 'pi_a' may be used uninitialized in this function [-Wmaybe-uninitialized] fout<<sum[pf_a][pf_b]-sum[pi_a-1][pf_b]-sum[pf_a][pi_b-1]+sum[pi_a-1][pi_b-1]; ~~~~^~ main.cpp:30:7: warning: 'pf_b' may be used uninitialized in this function [-Wmaybe-uninitialized] pf--; ^ main.cpp:49:24: note: 'pf_b' was declared here int pi_a,pi_b,pf_a,pf_b; ^~~~ main.cpp:67:59: warning: 'pi_b' may be used uninitialized in this function [-Wmaybe-uninitialized] fout<<sum[pf_a][pf_b]-sum[pi_a-1][pf_b]-sum[pf_a][pi_b-1]+sum[pi_a-1][pi_b-1]; ~~~~^~