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bff4ec7 | 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 | /*@ Import Lean
import Algorithms.maximum_subarray.lean.spec_lib
open scoped SimpleC
*/
/*@ Extern Coq
(MaxSubarraySumPrefix : list Z -> Z -> Z -> Prop)
*/
int max(int a, int b)
{
return (a > b) ? a : b;
}
int max_sub_array(int *arr, int n)
/*@ With (l : list Z)
Require
1 <= n && n <= 100000 &&
Zlength(l) == n &&
IntArray::full(arr, n, l) &&
(forall (k : Z), (0 <= k && k < n) => (-10000 <= l[k] && l[k] <= 10000))
Ensure
MaxSubarraySumPrefix(l, n, __return) &&
IntArray::full(arr, n, l)
*/
{
if (n == 0) {
return 0;
}
int cur = arr[0];
int res = arr[0];
for (int i = 1; i < n; i++) {
cur = max(arr[i], cur + arr[i]);
res = max(res, cur);
}
return res;
}
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