1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <stdint.h>
// DO NOT COPY THIS CODE INTO YOUR HOMEWORK FILES. This is the default always. Chance similarity
// is fine, but do not look at this while (or immediately before) doing your own
//
// You cannot use 0b######### syntax in ISO C11. It is non-standard and used only for this lecture.
uint8_t set_bit(uint8_t n, int bit_num_from_left) { // Longer name reduces ambiguity
// STUPID CODE - DO NOT CODE LIKE THIS
switch(bit_num_from_left) {
case 1:
return n | 0b10000000;
case 2:
return n | 0b01000000;
case 3:
return n | 0b00100000;
case 4:
return n | 0b00010000;
case 5:
return n | 0b00001000;
case 6:
return n | 0b00000100;
case 7:
return n | 0b00000010;
case 8:
return n | 0b00000001;
default:
assert(false); // shouldn't get here
}
}
// If I just said bit_num, you might ask if it is from the left or right. If I tell you, then
// you have to remember.
int main(int argc, char* argv[]) {
uint8_t n1 = 0b00000000;
uint8_t n2 = set_bit(n1, 1); // Set the FIRST bit
assert(set_bit(0, 1) == 0b10000000);
// ↑
assert(set_bit(0, 2) == 0b01000000);
// ↑
assert(set_bit(0, 8) == 0b00000001);
// ↑
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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