39 lines
682 B
Text
39 lines
682 B
Text
use std::cell::Cell;
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trait Arg {
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fn run(&self) -> i32;
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}
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impl Arg for i32 {
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fn run(&self) -> i32 { *self }
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}
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struct B<'a> {
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k: &'a Cell<i32>,
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x1: &'a Arg,
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x2: &'a Arg,
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x3: &'a Arg,
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x4: &'a Arg,
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}
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impl<'a> Arg for B<'a> {
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fn run(&self) -> i32 {
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self.k.set(self.k.get() - 1);
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a(self.k.get(), self, self.x1, self.x2, self.x3, self.x4)
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}
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}
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fn a(k: i32, x1: &Arg, x2: &Arg, x3: &Arg, x4: &Arg, x5: &Arg) -> i32 {
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if k <= 0 {
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x4.run() + x5.run()
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} else {
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B{
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k: &Cell::new(k),
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x1, x2, x3, x4
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}.run()
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}
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}
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pub fn main() {
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println!("{}", a(10, &1, &-1, &-1, &1, &0));
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}
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