2026PKUCourseHW5: fix type conversion and file open check #14512

Job	Run time
Build with GNU toolchain	1m 10s
Build extra components with Intel toolchain	50s
Build with CUDA support	1m 5s
Build extra components with GNU toolchain	26s
Build without LCAO and MPI	55s
Build with Intel toolchain	1m 7s
Build without MPI	11s
Build without ELPA	15s
Build without LCAO	34s
	6m 33s

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