tasks a-s

Task/Random-numbers/C/random-numbers.c

@@ -0,0 +1,22 @@
+#include <stdlib.h>
+#include <math.h>
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+double drand()   /* uniform distribution, (0..1] */
+{
+  return (rand()+1.0)/(RAND_MAX+1.0);
+}
+double random_normal()  /* normal distribution, centered on 0, std dev 1 */
+{
+  return sqrt(-2*log(drand())) * cos(2*M_PI*drand());
+}
+int main()
+{
+  int i;
+  double rands[1000];
+  for (i=0; i<1000; i++)
+    rands[i] = 1.0 + 0.5*random_normal();
+  return 0;
+}