Common sorted list: Difference between revisions
Added C solution
m (→{{header|Phix}}: missing the leading "?" shorthand) |
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Line 165:
<pre>
[5,1,3,8,9,4,8,7],[3,5,9,8,4],[1,3,7,9] : 1 3 4 5 7 8 9
</pre>
=={{header|C}}==
<lang c>#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define COUNTOF(a) (sizeof(a)/sizeof(a[0]))
void fatal(const char* message) {
fprintf(stderr, "%s\n", message);
exit(1);
}
void* xmalloc(size_t n) {
void* ptr = malloc(n);
if (ptr == NULL)
fatal("Out of memory");
return ptr;
}
void* xrealloc(void* p, size_t n) {
void* ptr = realloc(p, n);
if (ptr == NULL)
fatal("Out of memory");
return ptr;
}
int icompare(const void* p1, const void* p2) {
const int* ip1 = p1;
const int* ip2 = p2;
return (*ip1 < *ip2) ? -1 : ((*ip1 > *ip2) ? 1 : 0);
}
size_t unique(int* array, size_t len) {
size_t out_index = 0;
int prev;
for (size_t i = 0; i < len; ++i) {
if (i == 0 || prev != array[i])
array[out_index++] = array[i];
prev = array[i];
}
return out_index;
}
int* common_sorted_list(const int** arrays, const size_t* lengths, size_t count, size_t* size) {
size_t len = 0;
for (size_t i = 0; i < count; ++i)
len += lengths[i];
int* array = xmalloc(len * sizeof(int));
for (size_t i = 0, offset = 0; i < count; ++i) {
memcpy(array + offset, arrays[i], lengths[i] * sizeof(int));
offset += lengths[i];
}
qsort(array, len, sizeof(int), icompare);
*size = unique(array, len);
return array;
}
void print(int* array, size_t len) {
printf("[");
for (size_t i = 0; i < len; ++i) {
if (i > 0)
printf(", ");
printf("%d", array[i]);
}
printf("]\n");
}
int main() {
const int a[] = {5, 1, 3, 8, 9, 4, 8, 7};
const int b[] = {3, 5, 9, 8, 4};
const int c[] = {1, 3, 7, 9};
size_t len = 0;
const int* arrays[] = {a, b, c};
size_t lengths[] = {COUNTOF(a), COUNTOF(b), COUNTOF(c)};
int* sorted = common_sorted_list(arrays, lengths, COUNTOF(arrays), &len);
print(sorted, len);
free(sorted);
return 0;
}</lang>
{{out}}
<pre>
[1, 3, 4, 5, 7, 8, 9]
</pre>
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