Compilare: user.c: In function ‘main’: user.c:192:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d %d %d", &N, &M, &D); ^ user.c:195:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &val[i][j]); ^ user.c:282:10: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("mexc.out", "w", stdout); ^