Data update

Task/Greatest-subsequential-sum/FutureBasic/greatest-subsequential-sum.basic

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+_rndlen = 01   //BOOL: is sequence length random or fixed
+_maxlen = 14    //Length of each/longest sequence
+_maxVal = 20    //Largest number (pos or neg) in sequence
+_repeat = 25    //Number of sequences to evaluate
+
+void local fn maxSubSequence
+  int i, j, seq(_maxlen), ndx(_maxlen + 1),sum(_maxlen)
+  int grp, maxSum, maxNdx, maxEnd, tot, iterations = _repeat
+
+  while iterations
+    iterations--
+
+    // Create random sequence
+    int count = (_rndlen) ? rnd(_maxlen) : _maxlen
+    for i = 1 to count
+      seq(i) = rnd(_maxVal * 2 + 1) - _maxVal - 1
+    next
+
+    //  Determine maximum sub-sequence
+    bool isNeg = yes : grp = 0 : sum(0) = 0 : ndx(0) = 0
+    maxSum = 0 : maxNdx = 0 : maxEnd = 0
+
+    for i = 1 to count  // Merge array into groups of like signs
+      if (seq(i) < 0) <> isNeg  // If change of sign...
+        grp      ++              // Start new group
+        isNeg    = yes - isNeg
+        ndx(grp) = i
+        sum(grp) = 0
+      end if
+      sum(grp) += seq(i)
+    next
+    ndx(grp + 1) = 0
+
+    for i = 1 to grp step 2    // Determine max sub-sequence
+      j = i : tot = sum(j)
+      do
+        if tot > maxSum
+          maxSum = tot
+          maxNdx = ndx(i)
+          maxEnd = ndx(j + 1)
+        end if
+        j += 2 : tot += sum(j - 1) + sum(j) // add next neg & pos groups
+      until j > grp
+    next
+
+    // Print result
+    print @" Sum = "; maxSum, " {";
+    for i = 1 to count
+      if i == maxNdx then text ,,, _zCyan
+      if i == maxEnd then text ,,, fn ColorClear
+      print " "; seq(i); " ";
+    next
+    text ,,, fn ColorClear
+    print "}"
+
+  wend
+end fn
+
+window 1, @"Maximum subsequence"
+CFTimeInterval t : t = fn CACurrentMediaTime
+fn maxSubSequence
+printf @"\n %d random sequences created, solved, and printed in %.3f sec.",_repeat,1*(fn CACurrentMediaTime - t)
+
+handleevents