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  1. use std::collections::HashMap;
  2. fn f(m: usize) -> Option<[(u32, u32); 5]> {
  3.     let mut map = HashMap::<u64, [(u32, u32); 5]>::with_capacity(1 << 24);
  4.     for a in 1u64.. {
  5.         for b in 1..a {
  6.             let c = a * a * a - b * b * b;
  7.             let mut finished = false;
  8.             if !map.contains_key(&c) {
  9.                 map.insert(c, [(a as u32, b as u32), (0, 0), (0, 0), (0, 0), (0, 0)]);
  10.             } else if let Some(values) = map.get_mut(&c) {
  11.                 value_append(values, (a as u32, b as u32));
  12.                 finished = value_valid_size(values) == m;
  13.             }
  14.             if finished {
  15.                 return map.remove(&c);
  16.             }
  17.         }
  18.     }
  19.     return None;
  20. }
  21. fn value_valid_size(a: &[(u32, u32)]) -> usize {
  22.     a.iter().position(|&(a, _)| a == 0).unwrap_or(a.len())
  23. }
  24. fn value_append(a: &mut [(u32, u32)], b: (u32, u32)) {
  25.     let pos = value_valid_size(a);
  26.     if pos < a.len() {a[pos] = b;}
  27. }
  28. fn main() {
  29.     println!("{:?}", f(5))
  30. }
  31.  
Success #stdin #stdout 2.11s 1836776KB
comments (?)
stdin 
Standard input is empty
stdout 
Some([(1134, 357), (1155, 504), (1246, 805), (2115, 2004), (4746, 4725)])
https://ideone.com/G94aN3
language:
Rust (rust 1.56)
created:
79 days ago
visibility:
secret

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