Compilare: user.cpp: In function ‘int main()’: user.cpp:49:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph.size(); i++) { ^ user.cpp:53:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph.size(); i++) { ^ user.cpp:54:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < graph.size(); j++) { ^ user.cpp: In function ‘void dfs()’: user.cpp:76:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph.size(); i++) { ^ user.cpp:80:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < graph.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:28:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&N); ^ user.cpp:29:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&M); ^ user.cpp:39:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d",&start,&end); ^