Add solution 0821

leetcode/0643.Maximum-Average-Subarray-I/README.md

@@ -1,10 +1,4 @@
-# 643. Maximum Average Subarray I
-
-Added By: halfrost 
-Created Time: Feb 7, 2021 5:07 PM
-Difficulty: Easy
-Link: https://leetcode.com/problems/maximum-average-subarray-i/
-Tags: Array
+# [643. Maximum Average Subarray I](https://leetcode.com/problems/maximum-average-subarray-i/)
 
 ## 题目
 

leetcode/0821.Shortest-Distance-to-a-Character/821. Shortest Distance to a Character.go

@@ -0,0 +1,37 @@
+package leetcode
+
+import (
+	"math"
+)
+
+func shortestToChar(s string, c byte) []int {
+	res := make([]int, len(s))
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			res[i] = 0
+		} else {
+			left, right := math.MaxInt32, math.MaxInt32
+			for j := i + 1; j < len(s); j++ {
+				if s[j] == c {
+					right = j - i
+					break
+				}
+			}
+			for k := i - 1; k >= 0; k-- {
+				if s[k] == c {
+					left = i - k
+					break
+				}
+			}
+			res[i] = min(left, right)
+		}
+	}
+	return res
+}
+
+func min(a, b int) int {
+	if a > b {
+		return b
+	}
+	return a
+}

leetcode/0821.Shortest-Distance-to-a-Character/821. Shortest Distance to a Character_test.go

@@ -0,0 +1,48 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question821 struct {
+	para821
+	ans821
+}
+
+// para 是参数
+// one 代表第一个参数
+type para821 struct {
+	s string
+	c byte
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans821 struct {
+	one []int
+}
+
+func Test_Problem821(t *testing.T) {
+
+	qs := []question821{
+
+		{
+			para821{"loveleetcode", 'e'},
+			ans821{[]int{3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0}},
+		},
+
+		{
+			para821{"baaa", 'b'},
+			ans821{[]int{0, 1, 2, 3}},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 821------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans821, q.para821
+		fmt.Printf("【input】:%v       【output】:%v\n", p, shortestToChar(p.s, p.c))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0821.Shortest-Distance-to-a-Character/README.md

@@ -0,0 +1,76 @@
+# [821. Shortest Distance to a Character](https://leetcode.com/problems/shortest-distance-to-a-character/)
+
+
+## 题目
+
+Given a string `s` and a character `c` that occurs in `s`, return *an array of integers `answer` where* `answer.length == s.length` *and* `answer[i]` *is the shortest distance from* `s[i]` *to the character* `c` *in* `s`.
+
+**Example 1:**
+
+```
+Input: s = "loveleetcode", c = "e"
+Output: [3,2,1,0,1,0,0,1,2,2,1,0]
+```
+
+**Example 2:**
+
+```
+Input: s = "aaab", c = "b"
+Output: [3,2,1,0]
+```
+
+**Constraints:**
+
+- `1 <= s.length <= 104`
+- `s[i]` and `c` are lowercase English letters.
+- `c` occurs at least once in `s`.
+
+## 题目大意
+
+给定一个字符串 S 和一个字符 C。返回一个代表字符串 S 中每个字符到字符串 S 中的字符 C 的最短距离的数组。
+
+## 解题思路
+
+- 简单题。依次扫描字符串 S，针对每一个非字符 C 的字符，分别往左扫一次，往右扫一次，计算出距离目标字符 C 的距离，然后取左右两个距离的最小值存入最终答案数组中。
+
+## 代码
+
+```go
+package leetcode
+
+import (
+	"math"
+)
+
+func shortestToChar(s string, c byte) []int {
+	res := make([]int, len(s))
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			res[i] = 0
+		} else {
+			left, right := math.MaxInt32, math.MaxInt32
+			for j := i + 1; j < len(s); j++ {
+				if s[j] == c {
+					right = j - i
+					break
+				}
+			}
+			for k := i - 1; k >= 0; k-- {
+				if s[k] == c {
+					left = i - k
+					break
+				}
+			}
+			res[i] = min(left, right)
+		}
+	}
+	return res
+}
+
+func min(a, b int) int {
+	if a > b {
+		return b
+	}
+	return a
+}
+```