From efc7e67367abe85364e5ff037b53c7f4b51049a1 Mon Sep 17 00:00:00 2001
From: Yiyang Kang <kkyy@kkyy.me>
Date: Fri, 27 Mar 2026 11:28:00 +0900
Subject: [PATCH] add new solutions

---
 go.mod                         |  4 +-
 go.sum                         |  4 ++
 solutions/15/q1594/solution.go | 35 +++++++++++++++
 solutions/29/q2906/solution.go | 30 +++++++++++++
 solutions/29/q2946/solution.go | 27 ++++++++++++
 solutions/35/q3546/solution.go | 39 +++++++++++++++++
 solutions/35/q3548/solution.go | 78 ++++++++++++++++++++++++++++++++++
 7 files changed, 215 insertions(+), 2 deletions(-)
 create mode 100644 solutions/15/q1594/solution.go
 create mode 100644 solutions/29/q2906/solution.go
 create mode 100644 solutions/29/q2946/solution.go
 create mode 100644 solutions/35/q3546/solution.go
 create mode 100644 solutions/35/q3548/solution.go

diff --git a/go.mod b/go.mod
index 1ed0983..e3ebac8 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,6 @@ require (
 require (
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	golang.org/x/sys v0.41.0 // indirect
-	golang.org/x/text v0.34.0 // indirect
+	golang.org/x/sys v0.42.0 // indirect
+	golang.org/x/text v0.35.0 // indirect
 )
diff --git a/go.sum b/go.sum
index ab4f4a5..76c9906 100644
--- a/go.sum
+++ b/go.sum
@@ -9,5 +9,9 @@ github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
 golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
+golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
 golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
+golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
+golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
diff --git a/solutions/15/q1594/solution.go b/solutions/15/q1594/solution.go
new file mode 100644
index 0000000..7e3905d
--- /dev/null
+++ b/solutions/15/q1594/solution.go
@@ -0,0 +1,35 @@
+// Package q1594 implements a solution for https://leetcode.com/problems/maximum-non-negative-product-in-a-matrix/
+package q1594
+
+const MOD = 1e9 + 7
+
+func maxProductPath(grid [][]int) int {
+	buf := make([][2]int, len(grid[0]))
+
+	buf[0] = [2]int{grid[0][0], grid[0][0]}
+	for c := 1; c < len(grid[0]); c++ {
+		num := grid[0][c]
+		n1, n2 := num*buf[c-1][0], num*buf[c-1][1]
+		buf[c] = [2]int{max(n1, n2), min(n1, n2)}
+	}
+
+	for r := 1; r < len(grid); r++ {
+		num := grid[r][0]
+		n1, n2 := num*buf[0][0], num*buf[0][1]
+		buf[0] = [2]int{max(n1, n2), min(n1, n2)}
+
+		for c := 1; c < len(grid[0]); c++ {
+			num := grid[r][c]
+			n1, n2 := num*buf[c][0], num*buf[c][1]
+			n3, n4 := num*buf[c-1][0], num*buf[c-1][1]
+			buf[c] = [2]int{
+				max(n1, n2, n3, n4),
+				min(n1, n2, n3, n4),
+			}
+		}
+	}
+
+	return max(-1, buf[len(buf)-1][0]%MOD)
+}
+
+var _ = maxProductPath
diff --git a/solutions/29/q2906/solution.go b/solutions/29/q2906/solution.go
new file mode 100644
index 0000000..c068bf3
--- /dev/null
+++ b/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
diff --git a/solutions/29/q2946/solution.go b/solutions/29/q2946/solution.go
new file mode 100644
index 0000000..233905d
--- /dev/null
+++ b/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
diff --git a/solutions/35/q3546/solution.go b/solutions/35/q3546/solution.go
new file mode 100644
index 0000000..3a59eca
--- /dev/null
+++ b/solutions/35/q3546/solution.go
@@ -0,0 +1,39 @@
+// Package q3546 implements a solution for https://leetcode.com/problems/equal-sum-grid-partition-i/
+package q3546
+
+func chk(sums []int) bool {
+	sumAll := 0
+	for _, a := range sums {
+		sumAll += a
+	}
+	if sumAll%2 != 0 {
+		return false
+	}
+
+	target := sumAll / 2
+	sum := 0
+	for _, x := range sums {
+		sum += x
+		if sum == target {
+			return true
+		} else if sum > target {
+			return false
+		}
+	}
+	return false
+}
+
+func canPartitionGrid(grid [][]int) bool {
+	hSums := make([]int, len(grid[0]))
+	vSums := make([]int, len(grid))
+
+	for r := range grid {
+		for c := range grid[0] {
+			hSums[c] += grid[r][c]
+			vSums[r] += grid[r][c]
+		}
+	}
+	return chk(hSums) || chk(vSums)
+}
+
+var _ = canPartitionGrid
diff --git a/solutions/35/q3548/solution.go b/solutions/35/q3548/solution.go
new file mode 100644
index 0000000..764d534
--- /dev/null
+++ b/solutions/35/q3548/solution.go
@@ -0,0 +1,78 @@
+// Package q3548 implements a solution for https://leetcode.com/problems/equal-sum-grid-partition-ii/
+package q3548
+
+func findNumber(
+	num int,
+	r1, c1, r2, c2 int,
+	byVal map[int][][2]int32,
+	grid [][]int,
+) bool {
+	w, h := c2-c1+1, r2-r1+1
+	if w == 1 || h == 1 {
+		return grid[r1][c1] == num || grid[r2][c2] == num
+	}
+	for _, coord := range byVal[num] {
+		r, c := int(coord[0]), int(coord[1])
+		if r >= r1 && r <= r2 && c >= c1 && c <= c2 {
+			return true
+		}
+	}
+	return false
+}
+
+func canPartitionGrid(grid [][]int) bool {
+	w, h := len(grid[0]), len(grid)
+	hSums, vSums := make([]int, w), make([]int, h)
+	sumAll := 0
+	byVal := make(map[int][][2]int32, w*h)
+
+	for r := range h {
+		for c := range w {
+			val := grid[r][c]
+			hSums[c] += val
+			vSums[r] += val
+			sumAll += val
+			byVal[val] = append(byVal[val], [2]int32{int32(r), int32(c)})
+		}
+	}
+
+	// Check vertical cuts
+	sum := 0
+	for i := range w - 1 {
+		sum += hSums[i]
+		rem := sumAll - sum
+		if sum > rem {
+			if findNumber(sum-rem, 0, 0, h-1, i, byVal, grid) {
+				return true
+			}
+		} else if sum < rem {
+			if findNumber(rem-sum, 0, i+1, h-1, w-1, byVal, grid) {
+				return true
+			}
+		} else {
+			return true
+		}
+	}
+
+	// Check horizontal cuts
+	sum = 0
+	for i := range h - 1 {
+		sum += vSums[i]
+		rem := sumAll - sum
+		if sum > rem {
+			if findNumber(sum-rem, 0, 0, i, w-1, byVal, grid) {
+				return true
+			}
+		} else if sum < rem {
+			if findNumber(rem-sum, i+1, 0, h-1, w-1, byVal, grid) {
+				return true
+			}
+		} else {
+			return true
+		}
+	}
+
+	return false
+}
+
+var _ = canPartitionGrid