35 lines
983 B
D
35 lines
983 B
D
import std.stdio, std.string, std.conv, std.numeric,
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std.array, std.algorithm;
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bool isRectangular(T)(in T[][] M) pure nothrow {
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return M.all!(row => row.length == M[0].length);
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}
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T[][] matrixMul(T)(in T[][] A, in T[][] B) pure nothrow
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in {
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assert(A.isRectangular && B.isRectangular &&
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!A.empty && !B.empty && A[0].length == B.length);
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} body {
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auto result = new T[][](A.length, B[0].length);
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auto aux = new T[B.length];
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foreach (immutable j; 0 .. B[0].length) {
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foreach (immutable k, const row; B)
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aux[k] = row[j];
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foreach (immutable i, const ai; A)
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result[i][j] = dotProduct(ai, aux);
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}
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return result;
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}
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void main() {
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immutable a = [[1, 2], [3, 4], [3, 6]];
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immutable b = [[-3, -8, 3,], [-2, 1, 4]];
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immutable form = "[%([%(%d, %)],\n %)]]";
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writefln("A = \n" ~ form ~ "\n", a);
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writefln("B = \n" ~ form ~ "\n", b);
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writefln("A * B = \n" ~ form, matrixMul(a, b));
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}
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