#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int is_excluded(int num, const int *excluded, size_t excluded_size) {
for (size_t i = 0; i < excluded_size; ++i) {
if (excluded[i] == num) {
return 1;
}
}
return 0;
}
int random_excluding(int N, const int *excluded, size_t excluded_size) {
if (excluded_size > (size_t)(N + 1)) {
return -1;
}
srand((unsigned int)time(NULL));
int num;
do {
num = rand() % (N + 1);
} while (is_excluded(num, excluded, excluded_size));
return num;
}
int main() {
int excluded[] = {2, 5, 7};
size_t excluded_size = sizeof(excluded) / sizeof(excluded[0]);
int N = 14;
int result = random_excluding(N, excluded, excluded_size);
printf("%d\n", result);
return 0;
}
/*
run:
6
*/
