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#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#define WIDTH 12
int
main(int argc, char **argv) {
if (argc < 2) {
fprintf(stderr, "usage: %s datafile\n", *argv);
return 1;
}
FILE *fd = fopen(argv[1], "r");
if (fd == NULL) {
perror(argv[1]);
return 1;
}
int counts[WIDTH] = {0};
char *buf = NULL;
size_t buflen = 0;
int len = 0;
while (getline(&buf, &buflen, fd) != -1) {
len++;
for (int i = 0; i < WIDTH; i++)
counts[i] += buf[i] == '1' ? 1 : 0;
}
uint16_t gamma, epsilon;
gamma = epsilon = 0;
for (int i = 0; i < WIDTH; i++) {
if (counts[i] > len / 2)
gamma |= 1 << (WIDTH - 1 - i);
else
epsilon |= 1 << (WIDTH - 1 - i);
}
printf("epsilon: %d\ngamma: %d\n", epsilon, gamma);
printf("product: %d\n", epsilon * gamma);
free(buf);
if (fclose(fd) == EOF) {
perror("fclose");
return 1;
}
return 0;
}
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