Compilare: user.cpp: In function ‘int main()’: user.cpp:12:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%ld",&n); ^ user.cpp:18:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%ld",&a[i][0]); ^ user.cpp:19:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%ld",&a[i][1]); ^ user.cpp:53:21: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] a[pos][1]=-1; ^