A-M baby

Task/Greatest-subsequential-sum/D/greatest-subsequential-sum.d

@@ -0,0 +1,30 @@
+import std.stdio;
+
+inout(T[]) maxSubseq(T)(inout T[] sequence) pure nothrow {
+    int maxSum, thisSum, i, start, end = -1;
+
+    foreach (j, x; sequence) {
+        thisSum += x;
+        if (thisSum < 0) {
+            i = j + 1;
+            thisSum = 0;
+        } else if (thisSum > maxSum) {
+            maxSum = thisSum;
+            start = i;
+            end   = j;
+        }
+    }
+
+    if (start <= end && start >= 0 && end >= 0)
+        return sequence[start .. end + 1];
+    else
+        return [];
+}
+
+void main() {
+    const a1 = [-1, -2, 3, 5, 6, -2, -1, 4, -4, 2, -1];
+    writeln("Maximal subsequence: ", maxSubseq(a1));
+
+    const a2 = [-1, -2, -3, -5, -6, -2, -1, -4, -4, -2, -1];
+    writeln("Maximal subsequence: ", maxSubseq(a2));
+}