publish backlog of things

code-guessing/fibinput.c

@@ -0,0 +1,71 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <complex.h>
+#include <string.h>
+#include <stdlib.h>
+
+#define nfibs 93
+
+int64_t fibs[nfibs] = {0, 1, 0};
+
+void initf() {
+	for (int k = 2; k < nfibs; k++) {
+		fibs[k] = fibs[k-1] + fibs[k-2];
+	}
+}
+
+bool iusol[nfibs] = {0};
+
+int bsectf(int64_t n, int aa, int b) {
+	while (aa < b) {
+		int mid = (aa + b) >> 1;
+		if (fibs[mid] < n) { aa = mid + 1; }
+		else { b = mid; }
+	}
+	return aa;
+}
+
+int sumf(int64_t trg) {
+	int pt = bsectf(trg, 0, nfibs);
+	if (fibs[pt] == trg) {
+		iusol[pt] = true;
+		return 1;
+	}
+	for (int k = pt - 1; k > 1; k--) {
+		if (iusol[k]) continue;
+		iusol[k] = true;
+		if (sumf(trg - fibs[k])) return 1;
+		iusol[k] = false;
+	}
+	return 0;
+}
+
+long*f(int64_t trg, int*length) {
+	if (fibs[2] == 0) initf();
+	memset(iusol, 0, nfibs);
+	sumf(trg);
+	*length = 0;
+	for (int k = 0; k < nfibs; k++) {
+		if (iusol[k]) {
+			(*length)++;
+		}
+	}
+	int j = 0;
+	long*out = calloc(*length, sizeof(uint64_t));
+	for (int k = 0; k < nfibs; k++) {
+		if (iusol[k]) {
+			out[j] = k;
+			j++;
+		}
+	}
+	return out;
+}
+
+int main() {
+	initf();
+	for (int k = 0; k < 100; k++) {
+		sumf(1);
+		sumf(2);
+	}
+}