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author | jack <[email protected]> | 2024-06-14 13:13:15 -0600 |
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committer | jack <[email protected]> | 2024-06-14 13:13:15 -0600 |
commit | d343a3b18dbaca9297d4f7b2280c4a16f0a5c8aa (patch) | |
tree | 96df922dae2a5073d9a50ea70c7aae6aa37e3ebe /remove_nodes_linked_list.c | |
download | leetcode-d343a3b18dbaca9297d4f7b2280c4a16f0a5c8aa.tar.gz leetcode-d343a3b18dbaca9297d4f7b2280c4a16f0a5c8aa.zip |
initial
Diffstat (limited to 'remove_nodes_linked_list.c')
-rw-r--r-- | remove_nodes_linked_list.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/remove_nodes_linked_list.c b/remove_nodes_linked_list.c new file mode 100644 index 0000000..0bcae4f --- /dev/null +++ b/remove_nodes_linked_list.c @@ -0,0 +1,59 @@ +// 2487. Remove Nodes From Linked List +#include "leetcode.h" + +/* + * given the 'head' of a linked list, remove evey node which has a node with a + * greater value anywhere to the right side of it. return the 'head' of the + * modified linked list. + */ + +struct ListNode { + int val; + struct ListNode *next; +}; + +int depth(struct ListNode *head) { + int n = 0; + struct ListNode *tmp = head; + while (tmp) { + n++; + tmp = tmp->next; + } + return n; +} + +struct ListNode *removeNodes(struct ListNode *head) { + int n = depth(head), i = 0; + struct ListNode **arr = + (struct ListNode **)malloc(n * sizeof(struct ListNode *)); + struct ListNode *tmp = head; + while (tmp) { + arr[i] = tmp; + i++; + tmp = tmp->next; + } + bool *remove = (bool *)calloc(n, sizeof(bool)); + int max = arr[n - 1]->val; + for (int i = n - 2; i >= 0; i--) { + if (arr[i]->val < max) + remove[i] = true; + else if (arr[i]->val > max) + max = arr[i]->val; + } + struct ListNode *ans; + for (int i = 0; i < n; i++) { + if (!remove[i]) { + ans = arr[i]; + tmp = ans; + for (int j = i + 1; j < n; j++) + if (!remove[j]) { + tmp->next = arr[j]; + tmp = tmp->next; + } + tmp->next = NULL; + break; + } + } + free(arr), free(remove); + return ans; +} |