45 lines
1 KiB
C
45 lines
1 KiB
C
#include "hallo-welt.h"
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#ifndef HALLO
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#define HALLO "Hallo Welt"
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#endif
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void hallo_welt(void) { printf(HALLO); }
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int zweierkomplement(int32_t i) { return ~i + 1; }
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// use more then one int type
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const char *binaerzahl(int32_t bin) {
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char *str = malloc(sizeof(bin) * 8 +
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1); // Allocate 8 bits for actual data and 1 Bit for the \0
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// sign indicating the end of the string
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bool is_negative;
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if (!str)
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return NULL;
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if (bin < 0) {
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bin = zweierkomplement(bin);
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is_negative = true;
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}
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int32_t bb; // that way we keep the memory lighter
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printf(is_negative ? "-" : "");
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for (int i = sizeof(bin) * 8 - 1; i >= 0; i--) {
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bb = bin >> i;
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str[i] = (bb % 2 == 1) ? 1 : 0;
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printf("%d", str[i]);
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}
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str[sizeof(bin)] = '\0';
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return str;
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}
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int getint(void) {
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uint32_t i;
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printf("Geben Sie eine Dezimahlzahl ein: ");
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scanf("%u", &i);
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return i;
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}
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int main(void) { printf("%s", binaerzahl(getint())); }
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