Datasets:
File size: 1,422 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 | use vstd::prelude::*;
fn main() {}
verus!{
spec fn f1_count_identical(s1: Seq<i32>, s2: Seq<i32>, s3: Seq<i32>) -> int
decreases s1.len(), s2.len(), s3.len(),
{
if s1.len() == 0 || s2.len() == 0 || s3.len() == 0 {
0
} else {
f1_count_identical(s1.drop_last(), s2.drop_last(), s3.drop_last()) + if (s1.last() == s2.last()
&& s2.last() == s3.last()) {
1 as int
} else {
0 as int
}
}
}
fn f1_count_identical_position(arr1: &Vec<i32>, arr2: &Vec<i32>, arr3: &Vec<i32>) -> (count: usize)
requires
arr1.len() == arr2.len() && arr2.len() == arr3.len(),
{
let mut count = 0;
let mut index = 0;
while index < arr1.len()
{
if arr1[index] == arr2[index] && arr2[index] == arr3[index] {
count += 1;
}
index += 1;
}
count
}
spec fn step1(__hp0: Seq<i32>, __hp1: Seq<i32>, __hp2: Seq<i32>, outp: usize) -> bool {
(0 <= outp <= __hp0.len())
&& (f1_count_identical(__hp0, __hp1, __hp2) == outp)
}
fn chain_driver(arr1: &Vec<i32>, arr2: &Vec<i32>, arr3: &Vec<i32>) -> (r_final: usize)
requires
arr1.len() == arr2.len() && arr2.len() == arr3.len(),
ensures
step1(arr1@, arr2@, arr3@, r_final),
{
let x1 = f1_count_identical_position(arr1, arr2, arr3);
proof {
assert(step1(arr1@, arr2@, arr3@, x1));
}
x1
}
} // verus!
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