A: Reformat The String

Author: Shuo

problems/reformat-the-string/reformat_the_string.go

@@ -0,0 +1,26 @@
+package problem1417
+
+func reformat(s string) string {
+	i, j, l := 0, 1, len(s)
+	str := make([]byte, l+1)
+	for _, c := range s {
+		if '0' <= c && c <= '9' {
+			if i > l {
+				return ""
+			}
+			str[i], i = byte(c), i+2
+		} else if j > l {
+			return ""
+		} else {
+			str[j], j = byte(c), j+2
+		}
+	}
+	if i == l || j == l {
+		return string(str[:l])
+	}
+	if i == l-1 {
+		str[i] = str[0]
+		return string(str[1 : l+1])
+	}
+	return ""
+}

problems/reformat-the-string/reformat_the_string_test.go

@@ -0,0 +1,63 @@
+package problem1417
+
+import "testing"
+
+type testType struct {
+	in   string
+	want string
+}
+
+func TestReformat(t *testing.T) {
+	tests := [...]testType{
+		{
+			in:   "a0b1c2",
+			want: "0a1b2c",
+		},
+		{
+			in:   "leetcode",
+			want: "",
+		},
+		{
+			in:   "1229857369",
+			want: "",
+		},
+		{
+			in:   "covid2019",
+			want: "c0o1v9i2d",
+		},
+		{
+			in:   "ab123",
+			want: "1a2b3",
+		},
+		{
+			in:   "ec",
+			want: "",
+		},
+		{
+			in:   "abcd12345",
+			want: "1a2b3c4d5",
+		},
+		{
+			in:   "12345abcd",
+			want: "1a2b3c4d5",
+		},
+		{
+			in:   "77",
+			want: "",
+		},
+		{
+			in:   "1",
+			want: "1",
+		},
+		{
+			in:   "a",
+			want: "a",
+		},
+	}
+	for _, tt := range tests {
+		got := reformat(tt.in)
+		if got != tt.want {
+			t.Fatalf("in: %v, got: %v, want: %v", tt.in, got, tt.want)
+		}
+	}
+}