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Task/Combinations-and-permutations/Nim/combinations-and-permutations.nim

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+import bigints
+
+proc perm(n, k: int32): BigInt =
+  result = initBigInt 1
+  var
+    k = n - k
+    n = n
+  while n > k:
+    result *= n
+    dec n
+
+proc comb(n, k: int32): BigInt =
+  result = perm(n, k)
+  var k = k
+  while k > 0:
+    result = result div k
+    dec k
+
+echo "P(1000, 969) = ", perm(1000, 969)
+echo "C(1000, 969) = ", comb(1000, 969)