C语言 | Leetcode C语言题解之第30题串联所有单词的子串

题目：

题解：

typedef struct {char key[32];int val;UT_hash_handle hh;
} HashItem;int* findSubstring(char * s, char ** words, int wordsSize, int* returnSize){    int m = wordsSize, n = strlen(words[0]), ls = strlen(s);int *res = (int *)malloc(sizeof(int) * ls);int pos = 0;for (int i = 0; i < n; i++) {if (i + m * n > ls) {break;}HashItem *diff = NULL;char word[32] = {0};for (int j = 0; j < m; j++) {snprintf(word, n + 1, "%s", s + i + j * n);HashItem * pEntry = NULL;HASH_FIND_STR(diff, word, pEntry);if (NULL == pEntry) {pEntry = (HashItem *)malloc(sizeof(HashItem));strcpy(pEntry->key, word);pEntry->val = 0;HASH_ADD_STR(diff, key, pEntry);} pEntry->val++;            }for (int j = 0; j < m; j++) {HashItem * pEntry = NULL;HASH_FIND_STR(diff, words[j], pEntry);if (NULL == pEntry) {pEntry = (HashItem *)malloc(sizeof(HashItem));strcpy(pEntry->key, words[j]);pEntry->val = 0;HASH_ADD_STR(diff, key, pEntry);} pEntry->val--;if (pEntry->val == 0) {HASH_DEL(diff, pEntry);free(pEntry);}}for (int start = i; start < ls - m * n + 1; start += n) {if (start != i) {char word[32];snprintf(word, n + 1, "%s", s + start + (m - 1) * n);HashItem * pEntry = NULL;HASH_FIND_STR(diff, word, pEntry);if (NULL == pEntry) {pEntry = (HashItem *)malloc(sizeof(HashItem));strcpy(pEntry->key, word);pEntry->val = 0;HASH_ADD_STR(diff, key, pEntry);} pEntry->val++;if (pEntry->val == 0) {HASH_DEL(diff, pEntry);free(pEntry);}snprintf(word, n + 1, "%s", s + start - n);pEntry = NULL;HASH_FIND_STR(diff, word, pEntry);if (NULL == pEntry) {pEntry = (HashItem *)malloc(sizeof(HashItem));strcpy(pEntry->key, word);pEntry->val = 0;HASH_ADD_STR(diff, key, pEntry);} pEntry->val--;if (pEntry->val == 0) {HASH_DEL(diff, pEntry);free(pEntry);}}if (HASH_COUNT(diff) == 0) {res[pos++] = start;}}HashItem *curr, *tmp;HASH_ITER(hh, diff, curr, tmp) {HASH_DEL(diff, curr);  free(curr);      }}*returnSize = pos;return res;
}