add new solutions

solutions/29/q2906/solution.go

@@ -0,0 +1,30 @@
+// Package q2906 implements a solution for https://leetcode.com/problems/construct-product-matrix/
+package q2906
+
+const MOD = 12345
+
+func constructProductMatrix(grid [][]int) [][]int {
+	w, h := len(grid[0]), len(grid)
+	output := make([][]int, h)
+	output[0] = make([]int, w*h)
+	for i := h - 1; i >= 0; i-- {
+		output[i] = output[0][i*w : (i+1)*w]
+	}
+
+	suffix := 1
+	for i := w*h - 1; i >= 0; i-- {
+		y, x := i/w, i%w
+		output[y][x] = suffix
+		suffix = suffix * grid[y][x] % MOD
+	}
+
+	prefix := 1
+	for i := range w * h {
+		y, x := i/w, i%w
+		output[y][x] = output[y][x] * prefix % MOD
+		prefix = prefix * grid[y][x] % MOD
+	}
+	return output
+}
+
+var _ = constructProductMatrix

solutions/29/q2946/solution.go

@@ -0,0 +1,27 @@
+// Package q2946 implements a solution for https://leetcode.com/problems/matrix-similarity-after-cyclic-shifts/
+package q2946
+
+func areSimilar(mat [][]int, k int) bool {
+	w := len(mat[0])
+	k %= w
+	if k == 0 {
+		return true
+	}
+
+	for r := range mat {
+		for c := range w {
+			var shifted int
+			if r%2 == 0 {
+				shifted = (c + k) % w
+			} else {
+				shifted = (c + w - k) % w
+			}
+			if mat[r][shifted] != mat[r][c] {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+var _ = areSimilar