add: leetcode 0299 solution

leetcode/0299.Bulls-and-Cows/299.Bulls and Cows.go

@@ -0,0 +1,31 @@
+package leetcode
+
+import "strconv"
+
+func getHint(secret string, guess string) string {
+	cntA, cntB := 0, 0
+	mpS := make(map[byte]int)
+	var strG []byte
+	n := len(secret)
+	var ans string
+	for i := 0; i < n; i++ {
+		if secret[i] == guess[i] {
+			cntA++
+		} else {
+			mpS[secret[i]] += 1
+			strG = append(strG, guess[i])
+		}
+	}
+	for _, v := range strG {
+		if _, ok := mpS[v]; ok {
+			if mpS[v] > 1 {
+				mpS[v] -= 1
+			} else {
+				delete(mpS, v)
+			}
+			cntB++
+		}
+	}
+	ans += strconv.Itoa(cntA) + "A" + strconv.Itoa(cntB) + "B"
+	return ans
+}

leetcode/0299.Bulls-and-Cows/299.Bulls and Cows_test.go

@@ -0,0 +1,56 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question299 struct {
+	para299
+	ans299
+}
+
+// para 是参数
+type para299 struct {
+	secret string
+	guess  string
+}
+
+// ans 是答案
+type ans299 struct {
+	ans string
+}
+
+func Test_Problem299(t *testing.T) {
+
+	qs := []question299{
+
+		{
+			para299{"1807", "7810"},
+			ans299{"1A3B"},
+		},
+
+		{
+			para299{"1123", "0111"},
+			ans299{"1A1B"},
+		},
+
+		{
+			para299{"1", "0"},
+			ans299{"0A0B"},
+		},
+
+		{
+			para299{"1", "1"},
+			ans299{"1A0B"},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 299------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans299, q.para299
+		fmt.Printf("【input】:%v       【output】:%v\n", p, getHint(p.secret, p.guess))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0299.Bulls-and-Cows/README.md

@@ -0,0 +1,77 @@
+# [299. Bulls and Cows](https://leetcode-cn.com/problems/bulls-and-cows/)
+
+
+## 题目
+
+You are playing the Bulls and Cows game with your friend.
+
+You write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:
+
+The number of "bulls", which are digits in the guess that are in the correct position.
+The number of "cows", which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.
+Given the secret number secret and your friend's guess guess, return the hint for your friend's guess.
+
+The hint should be formatted as "xAyB", where x is the number of bulls and y is the number of cows. Note that both secret and guess may contain duplicate digits.
+
+**Example 1:**
+
+```
+Input: secret = "1807", guess = "7810"
+Output: "1A3B"
+Explanation: Bulls are connected with a '|' and cows are underlined:
+"1807"
+  |
+"7810"
+```
+
+**Example 2:**
+
+```
+Input: secret = "1123", guess = "0111"
+Output: "1A1B"
+Explanation: Bulls are connected with a '|' and cows are underlined:
+"1123"        "1123"
+  |      or     |
+"0111"        "0111"
+Note that only one of the two unmatched 1s is counted as a cow since the non-bull digits can only be rearranged to allow one 1 to be a bull.
+```
+
+**Example 3:**
+
+```
+Input: secret = "1", guess = "0"
+Output: "0A0B"
+```
+
+**Example 4:**
+
+```
+Input: secret = "1", guess = "1"
+Output: "1A0B"
+```
+
+**Constraints:**
+
+- 1 <= secret.length, guess.length <= 1000
+- secret.length == guess.length
+- secret and guess consist of digits only.
+
+## 题目大意
+
+你在和朋友一起玩 猜数字（Bulls and Cows）游戏，该游戏规则如下：
+
+写出一个秘密数字，并请朋友猜这个数字是多少。朋友每猜测一次，你就会给他一个包含下述信息的提示：
+
+猜测数字中有多少位属于数字和确切位置都猜对了（称为 "Bulls", 公牛），
+有多少位属于数字猜对了但是位置不对（称为 "Cows", 奶牛）。也就是说，这次猜测中有多少位非公牛数字可以通过重新排列转换成公牛数字。
+给你一个秘密数字secret 和朋友猜测的数字guess ，请你返回对朋友这次猜测的提示。
+
+提示的格式为 "xAyB" ，x 是公牛个数， y 是奶牛个数，A 表示公牛，B表示奶牛。
+
+请注意秘密数字和朋友猜测的数字都可能含有重复数字。
+
+## 解题思路
+
+- 计算下标一致并且对应下标的元素一致的个数，即x
+- secret和guess分别去除x个公牛的元素,剩下secret和guess求共同的元素个数就是y
+- 把x， y转换成字符串，分别与"A"和"B"进行拼接返回结果