61 lines
1.1 KiB
C
61 lines
1.1 KiB
C
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#include <stdio.h>
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int maxnum = -2147483648;
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void mkhashtable(const int *arr, const int size, int *table);
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void printNum(const int *arr, const int loc, const int size);
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int main(void) {
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int n;
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scanf("%d", &n);
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int arr[n];
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// Initialize array
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for (int i = 0; i < n; i++) {
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scanf("%d", &arr[i]);
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if (arr[i] > maxnum)
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maxnum = arr[i];
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}
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int hash[maxnum];
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mkhashtable(arr, n, hash);
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// Search
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int m;
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scanf("%d", &m);
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int tmp;
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for (int i = 0; i < m; i++) {
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scanf("%d", &tmp);
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if (tmp < 0 || tmp >= maxnum) { // Not in the hash table
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printf("NULL\n");
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} else {
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printNum(arr, hash[tmp], n);
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}
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}
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return 0;
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}
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void mkhashtable(const int *arr, const int size, int *table) {
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// Initialize
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for (int i = 0; i < maxnum; i++) {
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table[i] = -1;
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}
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// Fill values
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for (int i = 0; i < size; i++) {
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table[arr[i]] = i;
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}
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return;
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}
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void printNum(const int *arr, const int loc, const int size) {
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if (loc == -1) {
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printf("NULL\n");
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} else {
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if (loc - 1 >= 0)
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printf("%d ", arr[loc - 1]);
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if (loc + 1 <= size)
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printf("%d ", arr[loc + 1]);
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printf("\n");
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}
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}
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