Add: UTF-8 Validation

Author: openset

internal/leetcode/problems_status.go

@@ -37,6 +37,7 @@ var problemStatus = map[int]bool{
 	50:   true,
 	53:   true,
 	58:   true,
+	65:   true,
 	66:   true,
 	67:   true,
 	69:   true,
@@ -97,6 +98,7 @@ var problemStatus = map[int]bool{
 	371:  true,
 	383:  true,
 	387:  true,
+	393:  true,
 	412:  true,
 	413:  true,
 	414:  true,

problems/utf-8-validation/utf_8_validation.go

@@ -1 +1,21 @@
-package utf_8_validation
+package problem_393
+
+func validUtf8(data []int) bool {
+	u := 0
+	for _, v := range data {
+		if u == 0 && v>>7 == 0 { // 0b0
+			u = 0
+		} else if u == 0 && v>>5 == 6 { // 0b110
+			u = 1
+		} else if u == 0 && v>>4 == 14 { // 0b1110
+			u = 2
+		} else if u == 0 && v>>3 == 30 { // 0b11110
+			u = 3
+		} else if u > 0 && v>>6 == 2 { // 0b10
+			u--
+		} else {
+			return false
+		}
+	}
+	return u == 0
+}

problems/utf-8-validation/utf_8_validation_test.go

@@ -1 +1,39 @@
-package utf_8_validation
+package problem_393
+
+import "testing"
+
+type caseType struct {
+	input    []int
+	expected bool
+}
+
+func TestValidUtf8(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []int{197},
+			expected: false,
+		},
+		{
+			input:    []int{197, 130, 1},
+			expected: true,
+		},
+		{
+			input:    []int{235, 140, 4},
+			expected: false,
+		},
+		{
+			input:    []int{248},
+			expected: false,
+		},
+		{
+			input:    []int{194, 155, 231, 184, 185, 246, 176, 131, 161, 222, 174, 227, 162, 134, 241, 154, 168, 185, 218, 178, 229, 187, 139, 246, 178, 187, 139, 204, 146, 225, 148, 179, 245, 139, 172, 134, 193, 156, 233, 131, 154, 240, 166, 188, 190, 216, 150, 230, 145, 144, 240, 167, 140, 163, 221, 190, 238, 168, 139, 241, 154, 159, 164, 199, 170, 224, 173, 140, 244, 182, 143, 134, 206, 181, 227, 172, 141, 241, 146, 159, 170, 202, 134, 230, 142, 163, 244, 172, 140, 191},
+			expected: true,
+		},
+	}
+	for _, tc := range tests {
+		output := validUtf8(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}