Add solution and test-cases for problem 2528

Author: 0xff-dev

leetcode/2501-2600/2528.Maximize-the-Minimum-Powered-City/README.md

@@ -0,0 +1,49 @@
+# [2528.Maximize the Minimum Powered City][title]
+
+## Description
+You are given a **0-indexed** integer array `stations` of length `n`, where `stations[i]` represents the number of power stations in the `ith` city.
+
+Each power station can provide power to every city in a fixed **range**. In other words, if the range is denoted by r, then a power station at city `i` can provide power to all cities `j` such that `|i - j| <= r` and `0 <= i, j <= n - 1`.
+
+- Note that `|x|` denotes absolute value. For example, `|7 - 5| = 2` and `|3 - 10| = 7`.
+
+The **power** of a city is the total number of power stations it is being provided power from.
+
+The government has sanctioned building `k` more power stations, each of which can be built in any city, and have the same range as the pre-existing ones.
+
+Given the two integers `r` and `k`, return the **maximum possible minimum power** of a city, if the additional power stations are built optimally.
+
+**Note** that you can build the k power stations in multiple cities.
+
+**Example 1:**
+
+```
+Input: stations = [1,2,4,5,0], r = 1, k = 2
+Output: 5
+Explanation: 
+One of the optimal ways is to install both the power stations at city 1. 
+So stations will become [1,4,4,5,0].
+- City 0 is provided by 1 + 4 = 5 power stations.
+- City 1 is provided by 1 + 4 + 4 = 9 power stations.
+- City 2 is provided by 4 + 4 + 5 = 13 power stations.
+- City 3 is provided by 5 + 4 = 9 power stations.
+- City 4 is provided by 5 + 0 = 5 power stations.
+So the minimum power of a city is 5.
+Since it is not possible to obtain a larger power, we return 5.
+```
+
+**Example 2:**
+
+```
+Input: stations = [4,4,4,4], r = 0, k = 3
+Output: 4
+Explanation: 
+It can be proved that we cannot make the minimum power of a city greater than 4.
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/maximize-the-minimum-powered-city
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/2501-2600/2528.Maximize-the-Minimum-Powered-City/Solution.go

@@ -1,5 +1,59 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(stations []int, r int, k int) int64 {
+	n := len(stations)
+	cnt := make([]int64, n+1)
+	for i := 0; i < n; i++ {
+		left := max(0, i-r)
+		right := min(n, i+r+1)
+		cnt[left] += int64(stations[i])
+		cnt[right] -= int64(stations[i])
+	}
+
+	minVal := int64(stations[0])
+	sumTotal := int64(0)
+	for _, s := range stations {
+		if int64(s) < minVal {
+			minVal = int64(s)
+		}
+		sumTotal += int64(s)
+	}
+
+	lo, hi := minVal, sumTotal+int64(k)
+	var res int64 = 0
+
+	for lo <= hi {
+		mid := lo + (hi-lo)/2
+		if check(cnt, mid, r, k) {
+			res = mid
+			lo = mid + 1
+		} else {
+			hi = mid - 1
+		}
+	}
+	return res
+}
+
+func check(cnt []int64, val int64, r int, k int) bool {
+	n := len(cnt) - 1
+	diff := make([]int64, len(cnt))
+	copy(diff, cnt)
+	var sum int64 = 0
+	remaining := int64(k)
+
+	for i := 0; i < n; i++ {
+		sum += diff[i]
+		if sum < val {
+			add := val - sum
+			if remaining < add {
+				return false
+			}
+			remaining -= add
+			end := min(n, i+2*r+1)
+			diff[end] -= add
+			sum += add
+		}
+	}
+
+	return true
 }

leetcode/2501-2600/2528.Maximize-the-Minimum-Powered-City/Solution_test.go

@@ -9,31 +9,31 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name     string
+		stations []int
+		r, k     int
+		expect   int64
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 2, 4, 5, 0}, 1, 2, 5},
+		{"TestCase2", []int{4, 4, 4, 4}, 0, 3, 4},
 	}
 
 	//	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.stations, c.r, c.k)
 			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 %v",
+					c.expect, got, c.stations, c.r, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }