Compilare: main.cpp: In function 'int main()': main.cpp:37:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < g[a].size(); i++) { ~~^~~~~~~~~~~~~ main.cpp:43:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l.size(); i++) { ~~^~~~~~~~~~ main.cpp:19:31: 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:24:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^