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Task/Matrix-multiplication/Nim/matrix-multiplication.nim

@@ -0,0 +1,31 @@
+import strfmt
+
+type Matrix[M,N: static[int]] = array[M, array[N, float]]
+
+let a = [[1.0,  1.0,  1.0,   1.0],
+         [2.0,  4.0,  8.0,  16.0],
+         [3.0,  9.0, 27.0,  81.0],
+         [4.0, 16.0, 64.0, 256.0]]
+
+let b = [[  4.0  , -3.0  ,  4/3.0,  -1/4.0 ],
+         [-13/3.0, 19/4.0, -7/3.0,  11/24.0],
+         [  3/2.0, -2.0  ,  7/6.0,  -1/4.0 ],
+         [ -1/6.0,  1/4.0, -1/6.0,   1/24.0]]
+
+proc `$`(m: Matrix): string =
+  result = "(["
+  for r in m:
+    if result.len > 2: result.add "]\n ["
+    for val in r: result.add val.format("8.2f")
+  result.add "])"
+
+proc `*`[M,P,N](a: Matrix[M,P]; b: Matrix[P,N]): Matrix[M,N] =
+  for i in result.low .. result.high:
+    for j in result[0].low .. result[0].high:
+      for k in a[0].low .. a[0].high:
+        result[i][j] += a[i][k] * b[k][j]
+
+echo a
+echo b
+echo a * b
+echo b * a