Compilare: user.cpp: In function ‘void form(double)’: user.cpp:62:9: warning: unused variable ‘next’ [-Wunused-variable] int next, val; ^ user.cpp:62:15: warning: unused variable ‘val’ [-Wunused-variable] int next, val; ^ user.cpp: In function ‘void read()’: user.cpp:29:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &g); ^ user.cpp:36:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] cost[x][y] = cost[y][x] = z; ^ user.cpp: In function ‘int main()’: user.cpp:183:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trafic.in", "r", stdin); ^ user.cpp:184:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trafic.out", "w", stdout); ^ user.cpp: In function ‘void solve()’: user.cpp:173:20: warning: ‘keep’ may be used uninitialized in this function [-Wmaybe-uninitialized] if((double)keep/100 > dist1[n]) ^