sir-gon · sir-gon · Jan 6, 2026 · Jan 6, 2026 · Dec 16, 2025 · Dec 16, 2025
diff --git a/.github/workflows/go-lint.yml b/.github/workflows/go-lint.yml
@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["windows-2022", "ubuntu-24.04", "macos-14"]
-        go: ["1.24.x", "1.25.x"]
+        go: ["1.23.x", "1.24.x", "1.25.x"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v6
@@ -32,14 +32,8 @@ jobs:
 
       - run: go version
 
-      - name: Test Styling (gofmt)
-        run: gofmt -l . && echo '✔  Your code looks good.'
-
-      # yamllint disable rule:line-length
-      - name: Test Styling (analysis/modernize) Analyzer modernize
-        if: ${{ ! startsWith(matrix.go, '1.22') }}
-        run: go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -test ./...
-      # yamllint enable rule:line-length
+      - name: Test Styling (gofmt & modernize)
+        run: make test/styling
 
       - name: Lint (go vet)
         run: go vet -v ./...

diff --git a/.github/workflows/go-test.yml b/.github/workflows/go-test.yml
@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["windows-2022", "ubuntu-24.04", "macos-14"]
-        go: ["1.24.x", "1.25.x"]
+        go: ["1.23.x", "1.24.x", "1.25.x"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v6

diff --git a/Dockerfile b/Dockerfile
@@ -29,7 +29,7 @@ WORKDIR ${WORKDIR}
 
 RUN  apk add --update --no-cache make nodejs npm wget \
   && apk add --update --no-cache yamllint \
-  && npm install -g --ignore-scripts markdownlint-cli
+  && npm install -g --ignore-scripts markdownlint-cli@0.47.0
 
 ADD https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh ${WORKDIR}/
 RUN sh install.sh -b $(go env GOPATH)/bin v2.0.0 \

diff --git a/Makefile b/Makefile
@@ -39,6 +39,22 @@ PKG_LIST=$(go list ./... | grep -v /vendor/ | tr '\n' ' '| xargs echo -n)
 BUILDKIT_PROGRESS=plain
 CGO_ENABLED=0
 
+# Modernize tool versioning
+# Go 1.25 requires gopls v0.21.0+
+# Go 1.24 and below should use gopls v0.20.0
+GO_VERSION := $(shell go version | cut -d' ' -f3 | sed 's/go//')
+MODERNIZE_VER := v0.20.0
+
+# Check if Go version is 1.25 or higher
+IS_GO_125 := $(shell echo "$(GO_VERSION)" | awk -F. '{if ($$1 > 1 || ($$1 == 1 && $$2 >= 25)) print 1; else print 0}')
+
+ifeq ($(IS_GO_125),1)
+	MODERNIZE_VER := latest
+endif
+
+# Use GOTOOLCHAIN=auto to ensure the required toolchain is available if needed
+MODERNIZE_CMD := GOTOOLCHAIN=auto $(GO) run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@$(MODERNIZE_VER)
+
 .MAIN: test/coverage
 .PHONY: all clean coverage dependencies help list test
 .EXPORT_ALL_VARIABLES: # (2)
@@ -82,10 +98,10 @@ test/static: dependencies
 
 test/styling: dependencies
 	gofmt -l . && echo '✔  Your code looks good.'
-	$(GO) run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -test ./...
+	$(MODERNIZE_CMD) -test ./...
 
 format:
-	$(GO) run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix ./...
+	$(MODERNIZE_CMD) -fix ./...
 
 coverage.out: env dependencies
 	$(GOTEST) -v -covermode=atomic -coverprofile="coverage.out" ./exercises/...

diff --git a/README.md b/README.md
@@ -79,8 +79,8 @@ You can run tests in the following ways:
 installed in your SO.
 - [Install and run with make](#install-and-run-using-make) require runtime tools
 and "make" installed in your SO.
-- [Install and run in Docker](#install-and-running-with-docker-) require Docker and
-docker-compose installed.
+- [Install and run in Docker](#install-and-running-with-docker-) require Docker
+  and docker-compose installed.
 - (⭐️)
 [Install and in Docker with make](#install-and-running-with-docker--using-make)
 require docker-compose and make installed.

diff --git a/...kerrank/interview_preparation_kit/dictionaries_and_hashmaps/ctci-ransom-note.md b/...kerrank/interview_preparation_kit/dictionaries_and_hashmaps/ctci-ransom-note.md
@@ -49,7 +49,8 @@ The third line contains `n` space-separated strings, each `node[i]`.
 
 - $ 1 \leq m, n \leq 30000 $
 - $ 1 \leq $ length of `magazine[i]` and `note[i]` $ \leq 5 $
-- Each word consists of English alphabetic letters (i.e., `a` to `z` and `A` to `Z`).
+- Each word consists of English alphabetic letters (i.e., `a` to `z` and `A` to
+  `Z`).
 
 ## Sample Input 0
 

diff --git a/docs/hackerrank/interview_preparation_kit/greedy_algorithms/angry-children.md b/docs/hackerrank/interview_preparation_kit/greedy_algorithms/angry-children.md
@@ -140,4 +140,5 @@ max(1,2,3,4) - min(1,2,3,4) = 4 - 1 = 3
 
 ## Explanation 2
 
-Here `k = 2`. `arr' = [2, 2]` or `arr' = [1, 1]` give the minimum unfairness of `0`.
+Here `k = 2`. `arr' = [2, 2]` or `arr' = [1, 1]` give the minimum unfairness
+of `0`.
diff --git a/docs/hackerrank/interview_preparation_kit/greedy_algorithms/greedy-florist.md b/docs/hackerrank/interview_preparation_kit/greedy_algorithms/greedy-florist.md
@@ -74,7 +74,8 @@ the original price of each flower.
 
 ## Explanation 0
 
-There are `n = 3` flowers with costs `c = [2, 5, ,6]` and `k = 3` people in the group.
+There are `n = 3` flowers with costs `c = [2, 5, ,6]` and `k = 3` people
+in the group.
 If each person buys one flower,
 the total cost of prices paid is `2 + 5 + 6 = 13` dollars.
 Thus, we print `13` as our answer.

diff --git a/docs/projecteuler/problem0002.md b/docs/projecteuler/problem0002.md
@@ -1,6 +1,7 @@
 # [Even Fibonacci numbers](https://projecteuler.net/problem=2)
 
-Each new term in the Fibonacci sequence is generated by adding the previous two terms.
+Each new term in the Fibonacci sequence is generated by adding the previous
+two terms.
 By starting with 1 and 2, the first 10 terms will be:
 
 $ 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ... $

diff --git a/docs/projecteuler/problem0020.md b/docs/projecteuler/problem0020.md
@@ -3,6 +3,7 @@
 $ n! $ means $ n × (n − 1) × ... × 3 × 2 × 1 $
 
 For example, $ 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800 $,
-and the sum of the digits in the number $ 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27 $.
+and the sum of the digits in the number $ 10! $ is
+$ 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27 $.
 
 Find the sum of the digits in the number $ 100! $
diff --git a/exercises/projecteuler/problem0007_brute_force_test.go b/exercises/projecteuler/problem0007_brute_force_test.go
@@ -1,5 +1,4 @@
 //go:build bruteforce
-// +build bruteforce
 
 package projecteuler
 

diff --git a/exercises/projecteuler/problem0010_bruteforce_test.go b/exercises/projecteuler/problem0010_bruteforce_test.go
@@ -1,5 +1,4 @@
 //go:build bruteforce
-// +build bruteforce
 
 package projecteuler
 

diff --git a/exercises/projecteuler/problem0012_bruteforce_test.go b/exercises/projecteuler/problem0012_bruteforce_test.go
@@ -1,5 +1,4 @@
 //go:build bruteforce
-// +build bruteforce
 
 package projecteuler
 

diff --git a/exercises/projecteuler/problem0014_bruteforce_test.go b/exercises/projecteuler/problem0014_bruteforce_test.go
@@ -1,5 +1,4 @@
 //go:build bruteforce
-// +build bruteforce
 
 package projecteuler
 

diff --git a/exercises/projecteuler/problem0018_bruteforce_test.go b/exercises/projecteuler/problem0018_bruteforce_test.go
@@ -1,5 +1,4 @@
 //go:build bruteforce
-// +build bruteforce
 
 package projecteuler
 

diff --git a/exercises/projecteuler/problem0024.go b/exercises/projecteuler/problem0024.go
@@ -22,7 +22,7 @@ func factorial(n int) int {
 
 func permute(symbols string, target int) string {
 	choices := strings.Split(symbols, "")
-	answer := ""
+	var answer strings.Builder
 	minimum := 0
 
 	for len(choices) > 0 {
@@ -33,14 +33,14 @@ func permute(symbols string, target int) string {
 			index += 1
 			minimum += combos
 		}
-		answer += choices[index]
+		answer.WriteString(choices[index])
 		copy(choices[index:], choices[index+1:])
 		choices[len(choices)-1] = ""
 		choices = choices[:len(choices)-1]
 		minimum -= combos
 	}
 
-	return answer
+	return answer.String()
 }
 
 func Problem0024(inputElements string, inputPermutationToFind int) string {