Compilare: user.cpp: In function ‘int main()’: user.cpp:107:83: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d %d %d %d %d", &N, &M, &start.l, &start.c, &finish.l, &finish.c); ^ user.cpp:110:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &pay[i][j]); ^ user.cpp:120:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("taxa.out", "w", stdout); ^