zigzag_conversion

Author: hitzzc

zigzag_conversion/zigzag_conversion.go

@@ -0,0 +1,35 @@
+package zigzag_conversion
+
+const (
+	up   string = "up"
+	down        = "down"
+)
+
+func convert(s string, numRows int) string {
+	if numRows == 1 {
+		return s
+	}
+	runes := []rune(s)
+	rows := make([][]rune, numRows)
+	i := 0
+	status := down
+	for index := range runes {
+		rows[i] = append(rows[i], runes[index])
+		if status == down {
+			i++
+			if i == numRows-1 {
+				status = up
+			}
+		} else {
+			i--
+			if i == 0 {
+				status = down
+			}
+		}
+	}
+	retRunes := []rune{}
+	for index := range rows {
+		retRunes = append(retRunes, rows[index]...)
+	}
+	return string(retRunes)
+}

zigzag_conversion/zigzag_conversion_test.go

@@ -0,0 +1,29 @@
+package zigzag_conversion
+
+import (
+	"testing"
+)
+
+func TestConvert(t *testing.T) {
+	tests := []string{
+		"A",
+		"ABCDE",
+		"PAYPALISHIRING",
+	}
+	rows := []int{
+		1,
+		3,
+		3,
+	}
+	results := []string{
+		"A",
+		"AEBDC",
+		"PAHNAPLSIIGYIR",
+	}
+	caseNum := 3
+	for i := 0; i < caseNum; i++ {
+		if ret := convert(tests[i], rows[i]); ret != results[i] {
+			t.Fatalf("case %d failed\nactual: %s, expect: %s\n", i, ret, results[i])
+		}
+	}
+}