Compilare: main.cpp: In function 'int main()': main.cpp:32:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ main.cpp:15:38: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d", &n, &m, &s); ^ main.cpp:17:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &a, &b); ^