Compilare: main.cpp: In function 'void sortbybit(int, int)': main.cpp:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < q[0].size() ; i++ ) ~~^~~~~~~~~~~~~ main.cpp:26:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < q[1].size() ; i++ ) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:43:45: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d%d%d", &n, &a, &b, &c ) ; ^