171 accepted. 6ms > 3ms

Author: aQua

Algorithms/0171.excel-sheet-column-number/README.md

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+# [171. Excel Sheet Column Number](https://leetcode.com/problems/excel-sheet-column-number/)
+
+## 题目
+Related to question Excel Sheet Column Title
+Given a column title as appear in an Excel sheet, return its corresponding column number.
+
+For example:
+```
+    A -> 1
+    B -> 2
+    C -> 3
+    ...
+    Z -> 26
+    AA -> 27
+    AB -> 28 
+```
+
+## 解题思路
+
+见程序注释

Algorithms/0171.excel-sheet-column-number/excel-sheet-column-number.go

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+package Problem0171
+
+func titleToNumber(s string) int {
+	res := 0
+
+	for i := 0; i < len(s); i++ {
+		temp := int(s[i] - 'A' + 1)
+		res = res*26 + temp
+	}
+
+	return res
+}

Algorithms/0171.excel-sheet-column-number/excel-sheet-column-number_test.go

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+package Problem0171
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// tcs is testcase slice
+var tcs = []struct {
+	s   string
+	ans int
+}{
+
+	{
+		"AA",
+		27,
+	},
+
+	// 可以有多个 testcase
+}
+
+func Test_titleToNumber(t *testing.T) {
+	ast := assert.New(t)
+
+	for _, tc := range tcs {
+		fmt.Printf("~~%v~~\n", tc)
+		ast.Equal(tc.ans, titleToNumber(tc.s), "输入:%v", tc)
+	}
+}
+
+func Benchmark_titleToNumber(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tc := range tcs {
+			titleToNumber(tc.s)
+		}
+	}
+}