pwc257 solution in go

2 files changed, 305 insertions, 0 deletions

diff --git a/challenge-257/pokgopun/go/ch-1.go b/challenge-257/pokgopun/go/ch-1.go
new file mode 100644
index 0000000000..824821a951
--- /dev/null
+++ b/challenge-257/pokgopun/go/ch-1.go
@@ -0,0 +1,77 @@
+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-257/
+/*#
+
+Task 1: Smaller than Current
+
+Submitted by: [44]Mohammad Sajid Anwar
+     __________________________________________________________________
+
+   You are given a array of integers, @ints.
+
+   Write a script to find out how many integers are smaller than current
+   i.e. foreach ints[i], count ints[j] < ints[i] where i != j.
+
+Example 1
+
+Input: @ints = (5, 2, 1, 6)
+Output: (2, 1, 0, 3)
+
+For $ints[0] = 5, there are two integers (2,1) smaller than 5.
+For $ints[1] = 2, there is one integer (1) smaller than 2.
+For $ints[2] = 1, there is none integer smaller than 1.
+For $ints[3] = 6, there are three integers (5,2,1) smaller than 6.
+
+Example 2
+
+Input: @ints = (1, 2, 0, 3)
+Output: (1, 2, 0, 3)
+
+Example 3
+
+Input: @ints = (0, 1)
+Output: (0, 1)
+
+Example 4
+
+Input: @ints = (9, 4, 9, 2)
+Output: (2, 1, 2, 0)
+
+Task 2: Reduced Row Echelon
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type ints []int
+
+func (is ints) countSmaller() ints {
+	s := make(ints, len(is))
+	for i, v := range is {
+		for _, e := range is {
+			if e < v {
+				s[i]++
+			}
+		}
+	}
+	return s
+}
+
+func main() {
+	for _, data := range []struct {
+		input, output ints
+	}{
+		{ints{5, 2, 1, 6}, ints{2, 1, 0, 3}},
+		{ints{1, 2, 0, 3}, ints{1, 2, 0, 3}},
+		{ints{0, 1}, ints{0, 1}},
+		{ints{9, 4, 9, 2}, ints{2, 1, 2, 0}},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(data.input.countSmaller(), data.output)) // blank if ok, otherwise show the differences
+	}
+}
diff --git a/challenge-257/pokgopun/go/ch-2.go b/challenge-257/pokgopun/go/ch-2.go
new file mode 100644
index 0000000000..5a9363df93
--- /dev/null
+++ b/challenge-257/pokgopun/go/ch-2.go
@@ -0,0 +1,228 @@
+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-257/
+/*#
+
+Task 2: Reduced Row Echelon
+
+Submitted by: [45]Ali Moradi
+     __________________________________________________________________
+
+   Given a matrix M, check whether the matrix is in reduced row echelon
+   form.
+
+   A matrix must have the following properties to be in reduced row
+   echelon form:
+1. If a row does not consist entirely of zeros, then the first
+   nonzero number in the row is a 1. We call this the leading 1.
+2. If there are any rows that consist entirely of zeros, then
+   they are grouped together at the bottom of the matrix.
+3. In any two successive rows that do not consist entirely of zeros,
+   the leading 1 in the lower row occurs farther to the right than
+   the leading 1 in the higher row.
+4. Each column that contains a leading 1 has zeros everywhere else
+   in that column.
+
+   For example:
+[
+   [1,0,0,1],
+   [0,1,0,2],
+   [0,0,1,3]
+]
+
+   The above matrix is in reduced row echelon form since the first nonzero
+   number in each row is a 1, leading 1s in each successive row are
+   farther to the right, and above and below each leading 1 there are only
+   zeros.
+
+   For more information check out this wikipedia [46]article.
+
+Example 1
+
+    Input: $M = [
+                  [1, 1, 0],
+                  [0, 1, 0],
+                  [0, 0, 0]
+                ]
+    Output: 0
+
+Example 2
+
+    Input: $M = [
+                  [0, 1,-2, 0, 1],
+                  [0, 0, 0, 1, 3],
+                  [0, 0, 0, 0, 0],
+                  [0, 0, 0, 0, 0]
+                ]
+    Output: 1
+
+Example 3
+
+    Input: $M = [
+                  [1, 0, 0, 4],
+                  [0, 1, 0, 7],
+                  [0, 0, 1,-1]
+                ]
+    Output: 1
+
+Example 4
+
+    Input: $M = [
+                  [0, 1,-2, 0, 1],
+                  [0, 0, 0, 0, 0],
+                  [0, 0, 0, 1, 3],
+                  [0, 0, 0, 0, 0]
+                ]
+    Output: 0
+
+Example 5
+
+    Input: $M = [
+                  [0, 1, 0],
+                  [1, 0, 0],
+                  [0, 0, 0]
+                ]
+    Output: 0
+
+Example 6
+
+    Input: $M = [
+                  [4, 0, 0, 0],
+                  [0, 1, 0, 7],
+                  [0, 0, 1,-1]
+                ]
+    Output: 0
+     __________________________________________________________________
+
+   Last date to submit the solution 23:59 (UK Time) Sunday 25th February
+   2024.
+     __________________________________________________________________
+
+SO WHAT DO YOU THINK ?
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type row []int
+
+func (rw row) isAllZero() bool {
+	for _, v := range rw {
+		if v != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func (rw row) l1Pos() int {
+	for i, v := range rw {
+		if v == 1 {
+			return i
+		}
+	}
+	return -1
+}
+
+type matrix []row
+
+func (mt matrix) noButtomZeroes() matrix {
+	s := mt
+	l := len(mt)
+	lz := l
+	for l > 0 {
+		l--
+		if mt[l].isAllZero() {
+			s = mt[:l]
+			lz--
+		}
+		if l != lz {
+			break
+		}
+	}
+	return s
+}
+
+func (mt matrix) isSingleNonZeroColumn(col int) bool {
+	c := 0
+	for _, v := range mt.noButtomZeroes() {
+		if v[col] != 0 {
+			c++
+		}
+		if c > 1 {
+			return false
+		}
+	}
+	return c == 1
+}
+
+func (mt matrix) isReducedRowEchelon() bool {
+	l1p := -1
+	for _, v := range mt.noButtomZeroes() {
+		l1 := v.l1Pos()
+		if l1 < 0 || l1 < l1p || mt.isSingleNonZeroColumn(l1) == false {
+			return false
+		}
+		l1p = l1
+	}
+	return true
+}
+
+func main() {
+	for _, data := range []struct {
+		input  matrix
+		output bool
+	}{
+		{
+			matrix{
+				row{1, 1, 0},
+				row{0, 1, 0},
+				row{0, 0, 0},
+			}, false,
+		},
+		{
+			matrix{
+				row{0, 1, -2, 0, 1},
+				row{0, 0, 0, 1, 3},
+				row{0, 0, 0, 0, 0},
+				row{0, 0, 0, 0, 0},
+			}, true,
+		},
+		{
+			matrix{
+				row{1, 0, 0, 4},
+				row{0, 1, 0, 7},
+				row{0, 0, 1, -1},
+			}, true,
+		},
+		{
+			matrix{
+				row{0, 1, -2, 0, 1},
+				row{0, 0, 0, 0, 0},
+				row{0, 0, 0, 1, 3},
+				row{0, 0, 0, 0, 0},
+			}, false,
+		},
+		{
+			matrix{
+				row{0, 1, 0},
+				row{1, 0, 0},
+				row{0, 0, 0},
+			}, false,
+		},
+		{
+			matrix{
+				row{4, 0, 0, 0},
+				row{0, 1, 0, 7},
+				row{0, 0, 1, -1},
+			}, false,
+		},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(data.input.isReducedRowEchelon(), data.output)) // blank if ok, otherwise show the difference
+	}
+}