Compilare: main.cpp: In function 'int main()': main.cpp:30:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i!=sums[x].size();i++) { ~^~~~~~~~~~~~~~~~ main.cpp:13:42: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(F, "%d%d%d%d", &n, &k, &a, &b); ^ main.cpp:17:31: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(F, "%d", &l[x]); ^