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Task/Left-factorials/Sidef/left-factorials-1.sidef

@@ -0,0 +1,3 @@
+func left_fact(k) {
+    ^k -> map {|n| n! } -> sum(0)
+}

Task/Left-factorials/Sidef/left-factorials-2.sidef

@@ -0,0 +1,3 @@
+func left_fact(k) {
+    ^k -> reduce { |a,b| a + b! } + 1
+}

Task/Left-factorials/Sidef/left-factorials-3.sidef

@@ -0,0 +1,18 @@
+func left_fact(n) {
+    static cached    = 0
+    static factorial = 1
+    static leftfact  = 0
+ 
+    if (n < cached) {
+        cached    = 0
+        factorial = 1
+        leftfact  = 0
+    }
+ 
+    while (n > cached) {
+        leftfact  += factorial
+        factorial *= ++cached
+    }
+ 
+    leftfact
+}

Task/Left-factorials/Sidef/left-factorials-4.sidef

@@ -0,0 +1,9 @@
+for r in [range(0, 10), range(20, 110).by(10)] {
+    for i in r {
+        printf("!%d  = %s\n", i, left_fact(i));
+    }
+}
+
+for i in range(1000, 10000).by(1000) {
+    printf("!%d has %d digits.\n", i, left_fact(i).len);
+}