progs_sh := d01
progs_py := d02 d04
progs_go := d05 d15

progs := $(progs_sh) $(progs_py) $(progs_go)

.PHONY: all
all: $(addsuffix _ok.txt,$(progs))

.PHONY: clean
clean:
	rm -f $(addsuffix _out.txt,$(progs)) $(progs_go)

.PHONY: ok-%
ok-%: %_out.txt
	@cp -v $< $*_ok.txt

%_ok.txt: %_out.txt
	@test -f $@ || (echo $*:; cat $<)
	@test -f $@ && (diff -u $@ $< && touch $@) || exit 0

$(addsuffix _out.txt,$(progs_sh)): %_out.txt: %.sh
	./$< $*_input.txt > $@

$(addsuffix _out.txt,$(progs_py)): %_out.txt: %.py
	./$< $*_input.txt > $@

$(addsuffix _out.txt,$(progs_go)): %_out.txt: %
	./$< $*_input.txt > $@

$(progs_go): %: %.go
	go build -o $@ $<