Datasets:
File size: 1,586 Bytes
c62beea | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | use vstd::prelude::*;
fn main() {}
verus!{
fn f1_max_length_list(seq: &Vec<Vec<i32>>) -> (max_list: &Vec<i32>)
requires
seq.len() > 0,
{
let mut max_list = &seq[0];
let mut index = 1;
while index < seq.len()
{
if ((seq[index]).len() > max_list.len()) {
max_list = &seq[index];
}
index += 1;
}
max_list
}
fn f2_insert_before_each(arr: &Vec<i32>, elem: i32) -> (result: Vec<i32>)
{
let mut result: Vec<i32> = Vec::new();
let mut index = 0;
while index < arr.len()
{
result.push(elem);
result.push(arr[index]);
index += 1;
}
result
}
spec fn step1(__hp0: Seq<Vec<i32>>, outp: Seq<i32>) -> bool {
(forall|k: int| 0 <= k < __hp0.len() ==> outp.len() >= #[trigger] (__hp0[k]).len())
&& (exists|k: int| 0 <= k < __hp0.len() && outp =~= #[trigger] (__hp0[k]@))
}
spec fn step2(inp: Seq<i32>, p2_elem: i32, outp: Seq<i32>) -> bool {
(outp.len() == (2 * inp.len()))
&& (forall|k: int| 0 <= k < inp.len() ==> #[trigger] outp[2 * k] == p2_elem)
&& (forall|k: int| 0 <= k < inp.len() ==> #[trigger] outp[2 * k + 1] == inp[k])
}
fn chain_driver(seq: &Vec<Vec<i32>>, p2_elem: i32) -> (r_final: Vec<i32>)
requires
seq.len() > 0,
ensures
exists|v1: Seq<i32>| #[trigger] step1(seq@, v1) && step2(v1, p2_elem, r_final@),
{
let x1 = f1_max_length_list(seq);
let x2 = f2_insert_before_each(x1, p2_elem);
proof {
assert(step1(seq@, x1@));
assert(step2(x1@, p2_elem, x2@));
}
x2
}
} // verus!
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