Compilare: user.cpp: In function ‘int main()’: user.cpp:16:9: warning: unused variable ‘k’ [-Wunused-variable] int k=0, n, m, i, nr; ^ user.cpp:17:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %lld\n", &n, &m, &l); ^ user.cpp:20:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &a[i]); ^ user.cpp:30:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &a[i]); ^ user.cpp:54:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "\n"); ^ user.cpp:57:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &c); ^