75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
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#include <stdio.h>
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#include <stdint.h>
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#include <stdlib.h>
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/*
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hello world
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hello world
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hello
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world
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hello
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world
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world
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hello world
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abcd
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abcd
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*/
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uint64_t getHash(char const *s) {
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const int p = 31;
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uint64_t hash = 0, p_pow = 1;
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while(*s) {
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/* отнимаем 'a' от кода буквы и единицу прибавляем, чтобы у строки вида 'aaaaa' хэш был ненулевой */
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hash += (*s++ - 'a' + 1) * p_pow;
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p_pow *= p;
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}
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return hash;
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}
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uint64_t getHash2(char const *str)
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{
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uint64_t hash = 5381;
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int32_t c;
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while ((c = *str++))
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hash = ((hash<<5) + hash) + c;
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return hash;
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}
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uint64_t rol(uint64_t n, size_t shift) {
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return (n<<shift) | (n>>(64 - shift));
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}
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uint64_t getHash3(char const *s) {
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uint64_t result = 0x55555555;
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while (*s) {
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result ^= *s++;
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result = rol(result, 5);
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}
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return result;
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}
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enum {TOTAL_STRINGS=10};
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struct strings {
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char s[100];
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uint64_t hash;
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} strs[TOTAL_STRINGS];
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int cmphashes (const void *a, const void *b) {
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return ( (*(struct strings *)a).hash - (*(struct strings *)b).hash );
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}
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int main(void)
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{
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for(size_t i=0; i<TOTAL_STRINGS; i++) {
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scanf(" %[^\n]",strs[i].s);
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strs[i].hash = getHash(strs[i].s);
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}
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for(size_t i=0; i<TOTAL_STRINGS; i++)
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printf("%s: %llu\n",strs[i].s, strs[i].hash);
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qsort(strs, TOTAL_STRINGS, sizeof(struct strings), cmphashes);
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printf("---------------------Sorted strings------------------------\n");
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for(size_t i=0; i<TOTAL_STRINGS; i++)
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printf("%s: %llu\n",strs[i].s, strs[i].hash);
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return 0;
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}
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