Datasets:
File size: 2,038 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 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | use vstd::prelude::*;
fn main() {}
verus!{
fn f1_replace_last_element(first: &Vec<i32>, second: &Vec<i32>) -> (replaced_list: Vec<i32>)
requires
first.len() > 0,
{
let mut replaced_list = Vec::new();
let first_end = first.len() - 1;
let mut index = 0;
while index < first_end
{
replaced_list.push(first[index]);
index += 1;
}
index = 0;
while index < second.len()
{
replaced_list.push(second[index]);
index += 1;
}
replaced_list
}
fn f2_find_negative_numbers(arr: &Vec<i32>) -> (negative_list: Vec<i32>)
{
let mut negative_list: Vec<i32> = Vec::new();
let input_len = arr.len();
let mut index = 0;
while index < arr.len()
{
if (arr[index] < 0) {
negative_list.push(arr[index]);
}
index += 1;
}
negative_list
}
fn f3_contains_k(arr: &Vec<i32>, k: i32) -> (result: bool)
{
let mut index = 0;
while index < arr.len()
{
if (arr[index] == k) {
return true;
}
index += 1;
}
false
}
spec fn step1(__hp0: Seq<i32>, __hp1: Seq<i32>, outp: Seq<i32>) -> bool {
(outp == __hp0.subrange(0, __hp0.len() - 1).add(__hp1))
}
spec fn step2(inp: Seq<i32>, outp: Seq<i32>) -> bool {
(outp == inp.filter(|x: i32| x < 0))
}
spec fn step3(inp: Seq<i32>, p3_k: i32, outp: bool) -> bool {
(outp == (exists|i: int| 0 <= i < inp.len() && (inp[i] == p3_k)))
}
fn chain_driver(first: &Vec<i32>, second: &Vec<i32>, p3_k: i32) -> (r_final: bool)
requires
first.len() > 0,
ensures
exists|v1: Seq<i32>, v2: Seq<i32>| #[trigger] step1(first@, second@, v1) && #[trigger] step2(v1, v2) && step3(v2, p3_k, r_final),
{
let x1 = f1_replace_last_element(first, second);
let x2 = f2_find_negative_numbers(&x1);
let x3 = f3_contains_k(&x2, p3_k);
proof {
assert(step1(first@, second@, x1@));
assert(step2(x1@, x2@));
assert(step3(x2@, p3_k, x3));
}
x3
}
} // verus!
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