Compilare: user.c: In function ‘main’: user.c:33:5: warning: use of ‘ll’ length modifier with ‘f’ type character [-Wformat=] fscanf(file1, "%llf", &vertices[i].x); ^ user.c:34:5: warning: use of ‘ll’ length modifier with ‘f’ type character [-Wformat=] fscanf(file1, "%llf", &vertices[i].y); ^ user.c:36:1: warning: use of ‘ll’ length modifier with ‘f’ type character [-Wformat=] fprintf(file2, "%.5llf", PolygonArea(vertices, N)); ^ user.c:30:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^ user.c:33:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%llf", &vertices[i].x); ^ user.c:34:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%llf", &vertices[i].y); ^