Compilare: main.cpp: In function 'int main()': main.cpp:51:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < ans.size(); i++) { ~~^~~~~~~~~~~~ main.cpp:16:31: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ main.cpp:18:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &a, &b); ^