Compilare: user.cpp: In function ‘int main()’: user.cpp:77:13: warning: unused variable ‘v’ [-Wunused-variable] int i, u, v, cost; ^ user.cpp:77:16: warning: unused variable ‘cost’ [-Wunused-variable] int i, u, v, cost; ^ user.cpp:80:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d", &N, &M); ^ user.cpp:82:65: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d %d", &edge[i].u, &edge[i].v, &edge[i].cost); ^ user.cpp:99:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out", "w", stdout); ^