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/*local function gcd(a,b)
if b == 0 then return a end
return gcd(b, math.fmod(a, b))
end
local function lcm(a)
local out = a[1]
for i=2,#a do
out = ((a[i] * out)) / (gcd(a[i], out))
end
return out
end
*/
#include "math.h"
#include "stdint.h"
#include <stdlib.h>
#include <threads.h>
#include <pthread.h>
uint64_t gcd(uint64_t a, uint64_t b){
if(b == 0) return a;
return gcd(b, a % b);
}
uint64_t lcm(uint64_t* a, size_t len){
uint64_t out = a[0];
for(size_t i = 1; i != len; i++){
out = (a[i] * out) / gcd(a[i], out);
}
return out;
}
int l_lcm(lua_State* L){
luaL_checktype(L, 1, LUA_TTABLE);
size_t len = lua_objlen(L,1);
uint64_t* nums = malloc(sizeof * nums * len);
for(size_t i = 0; i <= len-1; i++){
lua_pushinteger(L,i+1);
lua_gettable(L,1);
nums[i] = luaL_checknumber(L, -1);
lua_pop(L,1);
}
lua_pushnumber(L, lcm(nums, len));
free(nums);
return 1;
}
thread_local uint16_t seedv[3] = {0, 0, 0};
int l_random(lua_State* L){
if(seedv[0] + seedv[1] + seedv[2] == 0){
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
uint64_t seed = (ts.tv_sec << 32) | ts.tv_nsec;
seedv[0] = seed;
seedv[1] = seed >> 16;
seedv[2] = seed >> 32;
}
size_t min = 1;
switch(lua_gettop(L)){
case 2:
min = lua_tointeger(L, 1);
lua_remove(L, 1);
case 1:
lua_pushinteger(L, (erand48(seedv) * (lua_tointeger(L, 1) - min + 1)) + min);
break;
case 0:
default:
lua_pushnumber(L, erand48(seedv));
}
return 1;
}
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