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pmalek/main.c

Last active Jun 13, 2016
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compare version c string like "1.2.10"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
/*
* Function used to compare version c strings like: "1.2.3" or "12.9.1314214"
*/
int compare_versions(char* first, char* second)
{
size_t first_last_dot1 = 0;
size_t first_last_dot2 = strcspn(first, ".");
size_t second_last_dot1 = 0;
size_t second_last_dot2 = strcspn(second, ".");
char* first_c = (char*)calloc(first_last_dot2 + 1, sizeof(char));
char* second_c = (char*)calloc(second_last_dot2 + 1, sizeof(char));
int first_max = first_last_dot2;
int second_max = second_last_dot2;
while(first_last_dot2 || second_last_dot2)
{
// first longer than second ( different only by last segment )
if(first_last_dot2 && !second_last_dot2) {
free(first_c);
free(second_c);
return 1;
}
// second longer than first ( different only by last segment )
if(!first_last_dot2 && second_last_dot2) {
free(first_c);
free(second_c);
return -1;
}
if(first_last_dot2 > first_max) {
first_max = first_last_dot2;
first_c = (char*)realloc(first_c, first_last_dot2 + 1);
}
memset(first_c, 0, first_last_dot2);
strncat(first_c, first + first_last_dot1, first_last_dot2);
int first_n = atoi(first_c);
first_last_dot1 += first_last_dot2 + 1;
first_last_dot2 = strcspn(first + first_last_dot1, ".");
if(second_last_dot2 > second_max) {
second_max = second_last_dot2;
second_c = (char*)realloc(second_c, second_last_dot2 + 1);
}
memset(second_c, 0, second_last_dot2);
strncat(second_c, second + second_last_dot1, second_last_dot2);
int second_n = atoi(second_c);
second_last_dot1 += second_last_dot2 + 1;
second_last_dot2 = strcspn(second + second_last_dot1, ".");
if (first_n != second_n)
{
free(first_c);
free(second_c);
if(first_n < second_n) return -1;
return 1;
}
}
free(first_c);
free(second_c);
return 0;
}
int main()
{
assert(0 == compare_versions("1.12345678.2", "1.12345678.2"));
assert(-1 == compare_versions("1", "1.0"));
assert(0 == compare_versions("1", "1"));
assert(0 == compare_versions("1.11.2", "1.11.2"));
assert(1 == compare_versions("1.3", "1.2"));
assert(-1 == compare_versions("4.1", "4.88"));
assert(1 == compare_versions("44.9.1", "44.8.2"));
assert(0 == compare_versions("1.11.24.5.123.12314214", "1.11.24.5.123.12314214"));
assert(-1 == compare_versions("1.11.24.5.123.12314214", "1.11.24.5.123.12314215"));
assert(1 == compare_versions("1.11.24.5.123.123142199", "1.11.24.5.123.12314215"));
return 0;
}
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