79 lines
1.5 KiB
C
79 lines
1.5 KiB
C
#include <stdlib.h>
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#include <stdio.h>
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#define BUFFER_SIZE 1024
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int main(void) {
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FILE *fp = fopen("input", "r");
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size_t lineCount = 0;
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char buffer[BUFFER_SIZE] = {0};
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// get number of lines
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size_t read = 0;
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while ((read = fread(&buffer, sizeof(char), BUFFER_SIZE, fp))) {
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for (size_t i = 0; i < read; i++) {
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if (buffer[i] == '\n') {
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lineCount++;
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}
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}
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}
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rewind(fp);
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// get data from file
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int* left = malloc((lineCount * 2 + 1) * sizeof(int));
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// haha pointer arithmetic go brrr
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int* right = left + lineCount;
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for (size_t i = 0; i < lineCount; i++) {
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int leftNum, rightNum;
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int numsGot = fscanf(fp, "%d %d\n", &leftNum, &rightNum);
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if (numsGot == 2) {
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left[i] = leftNum;
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right[i] = rightNum;
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}
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}
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for (size_t i = 0; i < lineCount - 1; i++) {
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size_t leftMin = i;
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size_t rightMin = i;
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for (size_t j = i + 1; j < lineCount; j++) {
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if (left[j] < left[leftMin]) {
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leftMin = j;
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}
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if (right[j] < right[rightMin]) {
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rightMin = j;
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}
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}
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if (leftMin != i) {
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int temp = left[i];
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left[i] = left[leftMin];
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left[leftMin] = temp;
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}
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if (rightMin != i) {
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int temp = right[i];
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right[i] = right[rightMin];
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right[rightMin] = temp;
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}
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}
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int sum = 0;
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for (size_t i = 0; i < lineCount; i++) {
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sum += abs(left[i] - right[i]);
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}
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printf("%d\n", sum);
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free(left);
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fclose(fp);
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return 0;
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}
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