reverse_integer

Author: hitzzc

README.md

@@ -8,5 +8,6 @@ leetcode for golang
 #### [4. median of two sorted arrays](https://github.com/hitzzc/go-leetcode/tree/master/median_of_two_sorted_arrays)
 #### [5. longest palindromic substring](https://github.com/hitzzc/go-leetcode/tree/master/longest_palindromic_substring)
 #### [6. zigzag conversion](https://github.com/hitzzc/go-leetcode/tree/master/zigzag_conversion)
+#### [7. reverse integer](https://github.com/hitzzc/go-leetcode/tree/master/reverse_integer)
 
 

reverse_integer/reverse_integer.go

@@ -0,0 +1,21 @@
+package reverse_integer
+
+func reverse(x int) int {
+	sign := 1
+	tmp := x
+	if x < 0 {
+		sign = -1
+		tmp = -1 * x
+	}
+	list := []int{}
+	for tmp > 9 {
+		list = append(list, tmp%10)
+		tmp = tmp / 10
+	}
+	list = append(list, tmp)
+	ret := 0
+	for i := 0; i < len(list); i++ {
+		ret = 10*ret + list[i]
+	}
+	return ret * sign
+}

reverse_integer/reverse_integer_test.go

@@ -0,0 +1,28 @@
+package reverse_integer
+
+import (
+	"testing"
+)
+
+func TestReverse(t *testing.T) {
+	tests := []int{
+		123,
+		-123,
+		0,
+		-1,
+		1534236469,
+	}
+	results := []int{
+		321,
+		-321,
+		0,
+		-1,
+		9646324351,
+	}
+	caseNum := 5
+	for i := 0; i < caseNum; i++ {
+		if ret := reverse(tests[i]); ret != results[i] {
+			t.Fatalf("case %d failed\nactual: %d, expect: %d\n", i, ret, results[i])
+		}
+	}
+}