Compilare: main.cpp: In function 'int main()': main.cpp:39:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (countSetBits(sum) == k) { ~~~~~~~~~~~~~~~~~~^~~~ main.cpp:23:23: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ main.cpp:24:23: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &k); ^ main.cpp:29:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &arr[i]); ^