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Estimated hours taken: 0.25 Branches: main tests/benchmarks/*.m: Move the declaration of main1/3 back into the interface section, so that the instructions on how to "test the performance of the benchmarks" in the Mmakefile still work. These predicates need to be exported so that they can be used as entry points for benchmarking.
122 lines
2.4 KiB
Mathematica
122 lines
2.4 KiB
Mathematica
% query
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%
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% David H. D. Warren
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%
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% query population and area database to find coun-
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% tries of approximately equal population density
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:- module query.
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:- interface.
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:- import_module io.
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:- pred main(io__state, io__state).
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:- mode main(di, uo) is cc_multi.
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:- pred main1(quad).
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:- mode main1(out) is nondet.
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:- implementation.
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:- import_module int, prolog.
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:- type quad ---> quad(string, int, string, int).
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main -->
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( { main1(Out), Out = quad(C1, D1, C2, D2) } ->
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io__write_string(C1),
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io__write_string(" has density "),
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io__write_int(D1),
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io__write_string(" while "),
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io__write_string(C2),
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io__write_string(" has density "),
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io__write_int(D2),
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io__write_string("\n")
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;
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io__write_string("No solutions\n")
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).
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main1(Out) :-
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query(Out).
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:- pred query(quad).
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:- mode query(out) is nondet.
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query(quad(C1, D1, C2, D2)) :-
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density(C1, D1),
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density(C2, D2),
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D1 > D2,
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T1 is 20 * D1,
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T2 is 21 * D2,
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T1 < T2.
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:- pred density(string, int).
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:- mode density(out, out) is nondet.
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density(C, D) :-
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pop(C, P),
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area(C, A),
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P100 is P * 100,
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D is P100 // A.
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:- pred pop(string, int).
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:- mode pop(out, out) is multidet.
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% populations in 100000s
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pop("china", 8250).
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pop("india", 5863).
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pop("ussr", 2521).
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pop("usa", 2119).
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pop("indonesia", 1276).
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pop("japan", 1097).
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pop("brazil", 1042).
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pop("bangladesh", 750).
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pop("pakistan", 682).
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pop("w_germany", 620).
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pop("nigeria", 613).
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pop("mexico", 581).
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pop("uk", 559).
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pop("italy", 554).
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pop("france", 525).
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pop("philippines", 415).
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pop("thailand", 410).
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pop("turkey", 383).
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pop("egypt", 364).
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pop("spain", 352).
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pop("poland", 337).
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pop("s_korea", 335).
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pop("iran", 320).
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pop("ethiopia", 272).
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pop("argentina", 251).
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:- pred area(string, int).
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:- mode area(in, out) is semidet.
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% areas in 1000s of square miles
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area("china", 3380).
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area("india", 1139).
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area("ussr", 8708).
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area("usa", 3609).
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area("indonesia", 570).
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area("japan", 148).
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area("brazil", 3288).
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area("bangladesh", 55).
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area("pakistan", 311).
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area("w_germany", 96).
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area("nigeria", 373).
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area("mexico", 764).
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area("uk", 86).
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area("italy", 116).
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area("france", 213).
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area("philippines", 90).
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area("thailand", 200).
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area("turkey", 296).
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area("egypt", 386).
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area("spain", 190).
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area("poland", 121).
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area("s_korea", 37).
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area("iran", 628).
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area("ethiopia", 350).
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area("argentina", 1080).
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