Compilare: user.cpp: In member function ‘void Graph::read(FILE*)’: user.cpp:86:65: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file, "%d %d", &number_of_vertices, &number_of_edges); ^ user.cpp:89:58: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file, "%d %d %d", &source, &target, &cost); ^ user.cpp: In function ‘int main()’: user.cpp:210:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("royfloyd.out", "w", stdout); ^ user.cpp:219:26: warning: ‘source’ is used uninitialized in this function [-Wuninitialized] floyd(source, target); ^ user.cpp:219:26: warning: ‘target’ is used uninitialized in this function [-Wuninitialized]