Add solution and test-cases for problem 789

Author: 0xff-dev

leetcode/701-800/0789.Escape-The-Ghosts/README.md

@@ -1,28 +1,37 @@
 # [789.Escape The Ghosts][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+You are playing a simplified PAC-MAN game on an infinite 2-D grid. You start at the point `[0, 0]`, and you are given a destination point `target = [xtarget, ytarget]` that you are trying to get to. There are several ghosts on the map with their starting positions given as a 2D array ghosts, where `ghosts[i] = [xi, yi]` represents the starting position of the `ith` ghost. All inputs are **integral coordinates**.
+
+Each turn, you and all the ghosts may independently choose to either **move 1 unit** in any of the four cardinal directions: north, east, south, or west, or **stay still**. All actions happen **simultaneously**.
+
+You escape if and only if you can reach the target **before** any ghost reaches you. If you reach any square (including the target) at the **same time** as a ghost, it **does not** count as an escape.
+
+Return `true` if it is possible to escape regardless of how the ghosts move, otherwise return `false`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: ghosts = [[1,0],[0,3]], target = [0,1]
+Output: true
+Explanation: You can reach the destination (0, 1) after 1 turn, while the ghosts located at (1, 0) and (0, 3) cannot catch up with you.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Escape The Ghosts
-```go
 ```
+Input: ghosts = [[1,0]], target = [2,0]
+Output: false
+Explanation: You need to reach the destination (2, 0), but the ghost at (1, 0) lies between you and the destination.
+```
+
+**Example 3:**
 
+```
+Input: ghosts = [[2,0]], target = [1,0]
+Output: false
+Explanation: The ghost can reach the target at the same time as you.
+```
 
 ## 结语
 

leetcode/701-800/0789.Escape-The-Ghosts/Solution.go

@@ -1,5 +1,24 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func distance(a, b int) int {
+	if a < 0 {
+		a = -a
+	}
+	if b < 0 {
+		b = -b
+	}
+	return a + b
+}
+
+func Solution(ghosts [][]int, target []int) bool {
+	a, b := target[0], target[1]
+	cmp := distance(a, b)
+	for _, g := range ghosts {
+		a, b = target[0]-g[0], target[1]-g[1]
+		tmp := distance(a, b)
+		if tmp <= cmp {
+			return false
+		}
+	}
+	return true
 }

leetcode/701-800/0789.Escape-The-Ghosts/Solution_test.go

@@ -10,30 +10,31 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		ghosts [][]int
+		target []int
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 0}, {0, 3}}, []int{0, 1}, true},
+		{"TestCase2", [][]int{{1, 0}}, []int{2, 0}, false},
+		{"TestCase3", [][]int{{2, 0}}, []int{1, 0}, false},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.ghosts, c.target)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.ghosts, c.target)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }