哈希大法好！
直接上代码
1 typedef struct HashTable { 2 int *data; 3 int *flag; 4 int size; 5 } HashTable; 6 7 HashTable *init(int n) { 8 HashTable *h = (HashTable *)malloc(sizeof(HashTable)); 9 h->data = (int *)malloc(sizeof(int) * n); 10 h->flag = (int *)calloc(sizeof(int), (n / 31 + 1)); 11 h->size = n; 12 return h; 13 } 14 15 int hash(int val) { 16 return val & 0x7fffffff; 17 } 18 19 int check(HashTable *h, int ind) { 20 int x = ind / 31, y = ind % 31; 21 return h->flag[x] & (1 << y); 22 } 23 24 void set(HashTable *h, int ind, int val) { 25 int x = ind / 31, y = ind % 31; 26 h->flag[x] |= (1 << y); 27 h->data[ind] = val; 28 return ; 29 } 30 31 void insert(HashTable *h, int val) { 32 int ind = hash(val) % h->size; 33 int times = 1; 34 while (check(h, ind)) { 35 ind += (times * times); 36 ind %= h->size; 37 } 38 set(h, ind, val); 39 return ; 40 } 41 42 int query(HashTable *h, int val) { 43 int ind = hash(val) % h->size; 44 int times = 1; 45 while (check(h, ind) && h->data[ind] != val) { 46 ind += (times * times); 47 ind %= h->size; 48 } 49 return check(h, ind); 50 } 51 52 void clear(HashTable *h) { 53 if (h == NULL) return ; 54 free(h->data); 55 free(h->flag); 56 free(h); 57 return ; 58 } 59 60 bool containsDuplicate(int* nums, int numsSize){ 61 HashTable *h = init(numsSize * 3); 62 for (int i = 0; i < numsSize; i++) { 63 if (query(h, nums[i])) { 64 clear(h); 65 return true; 66 } 67 insert(h, nums[i]); 68 } 69 clear(h); 70 return false; 71 }