Compilare: user.c: In function ‘read’: user.c:100:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &perm[i][j]); ^ user.c: In function ‘main’: user.c:135:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &N); ^ user.c:139:10: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("echival1.out", "w", stdout); ^