Add: Reverse String II

problems/reverse-string-ii/reverse_string_ii.go

@@ -1 +1,14 @@
 package reverse_string_ii
+
+func reverseStr(s string, k int) string {
+ss, l := []rune(s), len(s)-1
+for i := 0; i < l; i += 2 * k {
+for m, n := i, i+k-1; m < n; m, n = m+1, n-1 {
+if n > l {
+n = l
+}
+ss[m], ss[n] = ss[n], ss[m]
+}
+}
+return string(ss)
+}

problems/reverse-string-ii/reverse_string_ii_test.go

@@ -1 +1,40 @@
 package reverse_string_ii
+
+import "testing"
+
+type caseType struct {
+s string
+k int
+expected string
+}
+
+func TestReverseStr(t *testing.T) {
+tests := [...]caseType{
+{
+s: "abcdefg",
+k: 2,
+expected: "bacdfeg",
+},
+{
+s: "abcdefg",
+k: 4,
+expected: "dcbaefg",
+},
+{
+s: "abcd",
+k: 4,
+expected: "dcba",
+},
+{
+s: "abcdefg",
+k: 8,
+expected: "gfedcba",
+},
+}
+for _, tc := range tests {
+output := reverseStr(tc.s, tc.k)
+if output != tc.expected {
+t.Fatalf("input: %v %v, output: %v, expected: %v", tc.s, tc.k, output, tc.expected)
+}
+}
+}