Initial data commit

Task/Subtractive-generator/C/subtractive-generator.c

@@ -0,0 +1,43 @@
+#include<stdio.h>
+
+#define MOD 1000000000
+int state[55], si = 0, sj = 0;
+
+int subrand();
+
+void subrand_seed(int p1)
+{
+	int i, j, p2 = 1;
+
+	state[0] = p1 % MOD;
+	for (i = 1, j = 21; i < 55; i++, j += 21) {
+		if (j >= 55) j -= 55;
+		state[j] = p2;
+		if ((p2 = p1 - p2) < 0) p2 += MOD;
+		p1 = state[j];
+	}
+	si = 0;
+	sj = 24;
+	for (i = 0; i < 165; i++) subrand();
+}
+
+int subrand()
+{
+	int x;
+	if (si == sj) subrand_seed(0);
+
+	if (!si--) si = 54;
+	if (!sj--) sj = 54;
+	if ((x = state[si] - state[sj]) < 0) x += MOD;
+
+	return state[si] = x;
+}
+
+int main()
+{
+	subrand_seed(292929);
+	int i;
+	for (i = 0; i < 10; i++) printf("%d\n", subrand());
+
+	return 0;
+}