Compilare: user.cpp: In function ‘int main()’: user.cpp:36:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<graph[j].size(); k++) ~^~~~~~~~~~~~~~~~ user.cpp:40:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<graph[0].size(); k++) ~^~~~~~~~~~~~~~~~ user.cpp: In function ‘void read()’: user.cpp:13:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d",&n,&m); ^ user.cpp:22:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d",&x,&y); ^ user.cpp:24:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&cost[x][y]); ^