105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <string.h>
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#include "01_hashtable.c"
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house **process_next_house(house **hash_table, uint32_t *table_size, int32_t *x, int32_t *y, uint32_t *hcount) {
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//first check to see if we need to enlarge the hash table
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if (hash(*x, *y) > *table_size - 1) {
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*table_size = *table_size * 2;
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hash_table = ht_resize(hash_table, *table_size / 2, *table_size);
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}
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//process next house
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house *loc = ht_lookup(hash_table, *x, *y);
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if (loc == NULL) {
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(*hcount)++;
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ht_insert(hash_table, *x, *y, 1);
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} else {
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(loc->p)++;
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}
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return hash_table;
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}
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int main() {
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FILE *file = fopen("input", "r");
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if (file == NULL) {
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perror("main: error opening file.");
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return 1;
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}
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uint32_t table_size = 25;
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house **hash_table = ht_init(table_size);
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/* Santa */
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int32_t x_s = 0;
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int32_t y_s = 0;
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ht_insert(hash_table, x_s, y_s, 1); //initial house at (0, 0)
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uint32_t hcount = 1;
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/* Robo-Santa */
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int32_t x_r = 0;
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int32_t y_r = 0;
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enum toggle {
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santa,
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robo_santa
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};
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enum toggle turn = robo_santa;
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int32_t c;
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while ((c = fgetc(file)) != EOF) {
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turn = turn ^ robo_santa; //toggle turn
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switch(turn) {
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case santa:
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if (c == '^') {
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y_s++;
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hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
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} else if (c == 'v') {
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y_s--;
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hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
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} else if (c == '>') {
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x_s++;
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hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
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} else if (c == '<') {
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x_s--;
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hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
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}
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break;
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case robo_santa:
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if (c == '^') {
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y_r++;
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hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
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} else if (c == 'v') {
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y_r--;
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hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
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} else if (c == '>') {
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x_r++;
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hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
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} else if (c == '<') {
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x_r--;
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hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
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}
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break;
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default:
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perror("main: turn error.");
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return -1;
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}
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}
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if (ferror(file)) {
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perror("main: error reading from file.");
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return -1;
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}
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fclose(file);
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printf("unique houses: %u\n", hcount);
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for (uint32_t i = 0; i < table_size; i++) {
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free(hash_table[i]);
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}
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free(hash_table);
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return 0;
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}
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