Import GNU bc 1.04

PR:		4183

4 files changed, 141 insertions, 0 deletions

diff --git a/contrib/bc/Examples/ckbook.b b/contrib/bc/Examples/ckbook.b
new file mode 100644
index 0000000..5815ea0
--- /dev/null
+++ b/contrib/bc/Examples/ckbook.b
@@ -0,0 +1,16 @@
+scale=2
+print "\nCheck book program!\n"
+print "  Remember, deposits are negative transactions.\n"
+print "  Exit by a 0 transaction.\n\n"
+
+print "Initial balance? "; bal = read()
+bal /= 1
+print "\n"
+while (1) {
+  "current balance = "; bal
+  "transaction? "; trans = read()
+  if (trans == 0) break;
+  bal -= trans
+  bal /= 1
+}
+quit
diff --git a/contrib/bc/Examples/pi.b b/contrib/bc/Examples/pi.b
new file mode 100644
index 0000000..0d840cf
--- /dev/null
+++ b/contrib/bc/Examples/pi.b
@@ -0,0 +1,53 @@
+/*
+   This is a program to determine the distribution of digits in the
+   fraction part of PI.   It will look at the first scale digits.
+
+   The results are left in the global variable digits.
+   digits[0] is the number of 0's in PI.
+
+   This program requires the math library.
+*/
+
+define pi () {
+  auto ix, pi, save_scale, work;
+
+  save_scale = scale;
+  scale += 5;
+  print "\n\nCalculating PI to ",scale," digits.  Please wait . . .";
+  pi = 4*a(1);
+  scale -= 5;
+  work = pi;
+
+  print "\nCounting digits. . .";
+  for (ix = 0; ix < 10; ix++) digits[ix] = 0;
+
+  /* Extract the One's digit from pi. */
+  scale = 0;
+  one_digit = work / 1;
+
+  for (ix = save_scale; ix > 0; ix--) {
+
+    /* Remove the One's digit and multiply by 10. */
+    scale = ix;
+    work = (work - one_digit) / 1 * 10;
+
+    /* Extract the One's digit. */
+    scale = 0;
+    one_digit = work / 1;
+
+    digits[one_digit] += 1;
+  }
+
+  /* Restore the scale. */
+  scale = save_scale;
+
+  /* Report. */
+  print "\n\n"
+  print "PI to ", scale, " digits is:\n", pi/1, "\n\n"
+  print "The frequency of the digits are:\n"
+  for (ix = 0; ix < 10; ix++) {
+    print "    ", ix, " - ", digits[ix], " times\n"
+  }
+
+  print "\n\n"
+}
diff --git a/contrib/bc/Examples/primes.b b/contrib/bc/Examples/primes.b
new file mode 100644
index 0000000..2b52ca7
--- /dev/null
+++ b/contrib/bc/Examples/primes.b
@@ -0,0 +1,32 @@
+
+/* An example that finds all primes between 2 and limit. */
+
+define primes (limit) {
+    auto num, p, root, i
+
+    prime[1] = 2;
+    prime[2] = 3;
+    num = 2;
+    if (limit >= 2) print "prime 1 = 2\n"
+    if (limit >= 3) print "prime 2 = 3\n";
+    scale = 0;
+
+    for ( p=5; p <= limit; p += 2)  {
+	root = sqrt(p);
+	isprime = 1;
+	for ( i = 1;  i < num && prime[i] <= root; i++ ) {
+	    if ( p % prime[i] == 0 ) {
+		isprime = 0;
+		break;
+            }
+	}
+	if (isprime) {
+	    num += 1;
+	    prime [num] = p;
+	    print "prime ", num, " = ", p, "\n"
+	}
+     }
+}
+
+
+print "\ntyping 'primes (10)' will print all primes less than 10.\n"
diff --git a/contrib/bc/Examples/twins.b b/contrib/bc/Examples/twins.b
new file mode 100644
index 0000000..de910a7
--- /dev/null
+++ b/contrib/bc/Examples/twins.b
@@ -0,0 +1,40 @@
+
+/* An example that finds all primes between 2 and limit. */
+
+define primes (limit) {
+    auto num, p, root, i
+
+    prime[1] = 2;
+    prime[2] = 3;
+    num = 2;
+    scale = 0;
+
+    for ( p=5; p <= limit; p += 2)  {
+	root = sqrt(p);
+	isprime = 1;
+	for ( i = 1;  i < num && prime[i] <= root; i++ ) {
+	    if ( p % prime[i] == 0 ) {
+		isprime = 0;
+		break;
+            }
+	}
+	if (isprime) {
+	    num += 1;
+	    prime [num] = p;
+	}
+     }
+}
+
+
+print "\ntyping 'twins (10)' will print all twin primes less than 10.\n"
+
+define twins (limit) {
+   auto i;
+
+   i = primes(limit+2);
+
+   for (i=1; prime[i] > 0; i++) {
+      if ((prime[i]+2) == prime[i+1]) \
+	print "twins are ", prime[i], " and ", prime[i+1], "\n"
+   }
+}