feat: add solutions to lc problem: No.3081 (doocs#2457)

yanglbme · web-flow · commit e2b21d8950bc · 2024-03-18T17:19:42.000+08:00
No.3081.Replace Question Marks in String to Minimize Its Value
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/README.md b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/README.md
@@ -72,24 +72,152 @@
 
 ## 解法
 
-### 方法一
+### 方法一：贪心 + 优先队列
+
+根据题目，我们可以发现，如果一个字母 $c$ 出现的次数为 $v$，那么它对答案贡献的分数为 $1 + 2 + \cdots + (v - 1) = \frac{v \times (v - 1)}{2}$。为了使得答案尽可能小，我们应该尽量替换问号为那些出现次数较少的字母。
+
+因此，我们可以使用优先队列（小根堆）来维护每个字母的出现次数，每次取出出现次数最少的字母，将其记录到数组 $t$ 中，然后将其出现次数加一，再放回优先队列中。最后，我们将数组 $t$ 排序，然后遍历字符串 $s$，将每个问号依次替换为数组 $t$ 中的字母即可。
+
+时间复杂度 $O(n \times \log n)$，空间复杂度 $O(n)$。其中 $n$ 为字符串 $s$ 的长度。
 
 <!-- tabs:start -->
 
 ```python
-
+class Solution:
+    def minimizeStringValue(self, s: str) -> str:
+        cnt = Counter(s)
+        pq = [(cnt[c], c) for c in ascii_lowercase]
+        heapify(pq)
+        t = []
+        for _ in range(s.count("?")):
+            v, c = pq[0]
+            t.append(c)
+            heapreplace(pq, (v + 1, c))
+        t.sort()
+        cs = list(s)
+        j = 0
+        for i, c in enumerate(s):
+            if c == "?":
+                cs[i] = t[j]
+                j += 1
+        return "".join(cs)
 ```
 
 ```java
-
+class Solution {
+    public String minimizeStringValue(String s) {
+        int[] cnt = new int[26];
+        int n = s.length();
+        int k = 0;
+        char[] cs = s.toCharArray();
+        for (char c : cs) {
+            if (c == '?') {
+                ++k;
+            } else {
+                ++cnt[c - 'a'];
+            }
+        }
+        PriorityQueue<int[]> pq
+            = new PriorityQueue<>((a, b) -> a[0] == b[0] ? a[1] - b[1] : a[0] - b[0]);
+        for (int i = 0; i < 26; ++i) {
+            pq.offer(new int[] {cnt[i], i});
+        }
+        int[] t = new int[k];
+        for (int j = 0; j < k; ++j) {
+            int[] p = pq.poll();
+            t[j] = p[1];
+            pq.offer(new int[] {p[0] + 1, p[1]});
+        }
+        Arrays.sort(t);
+
+        for (int i = 0, j = 0; i < n; ++i) {
+            if (cs[i] == '?') {
+                cs[i] = (char) (t[j++] + 'a');
+            }
+        }
+        return new String(cs);
+    }
+}
 ```
 
 ```cpp
-
+class Solution {
+public:
+    string minimizeStringValue(string s) {
+        int cnt[26]{};
+        int k = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                ++k;
+            } else {
+                ++cnt[c - 'a'];
+            }
+        }
+        priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
+        for (int i = 0; i < 26; ++i) {
+            pq.push({cnt[i], i});
+        }
+        vector<int> t(k);
+        for (int i = 0; i < k; ++i) {
+            auto [v, c] = pq.top();
+            pq.pop();
+            t[i] = c;
+            pq.push({v + 1, c});
+        }
+        sort(t.begin(), t.end());
+        int j = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                c = t[j++] + 'a';
+            }
+        }
+        return s;
+    }
+};
 ```
 
 ```go
-
+func minimizeStringValue(s string) string {
+	cnt := [26]int{}
+	k := 0
+	for _, c := range s {
+		if c == '?' {
+			k++
+		} else {
+			cnt[c-'a']++
+		}
+	}
+	pq := hp{}
+	for i, c := range cnt {
+		heap.Push(&pq, pair{c, i})
+	}
+	t := make([]int, k)
+	for i := 0; i < k; i++ {
+		p := heap.Pop(&pq).(pair)
+		t[i] = p.c
+		p.v++
+		heap.Push(&pq, p)
+	}
+	sort.Ints(t)
+	cs := []byte(s)
+	j := 0
+	for i, c := range cs {
+		if c == '?' {
+			cs[i] = byte(t[j] + 'a')
+			j++
+		}
+	}
+	return string(cs)
+}
+
+type pair struct{ v, c int }
+type hp []pair
+
+func (h hp) Len() int           { return len(h) }
+func (h hp) Less(i, j int) bool { return h[i].v < h[j].v || h[i].v == h[j].v && h[i].c < h[j].c }
+func (h hp) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+func (h *hp) Push(v any)        { *h = append(*h, v.(pair)) }
+func (h *hp) Pop() any          { a := *h; v := a[len(a)-1]; *h = a[:len(a)-1]; return v }
 ```
 
 <!-- tabs:end -->
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/README_EN.md b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/README_EN.md
@@ -68,24 +68,152 @@
 
 ## Solutions
 
-### Solution 1
+### Solution 1: Greedy + Priority Queue
+
+According to the problem, we can find that if a letter $c$ appears $v$ times, then the score it contributes to the answer is $1 + 2 + \cdots + (v - 1) = \frac{v \times (v - 1)}{2}$. To make the answer as small as possible, we should replace the question marks with those letters that appear less frequently.
+
+Therefore, we can use a priority queue to maintain the occurrence times of each letter, take out the letter with the least occurrence times each time, record it in the array $t$, then increase its occurrence times by one, and put it back into the priority queue. Finally, we sort the array $t$, and then traverse the string $s$, replacing each question mark with the letters in the array $t$ in turn.
+
+The time complexity is $O(n \times \log n)$, and the space complexity is $O(n)$. Where $n$ is the length of the string $s$.
 
 <!-- tabs:start -->
 
 ```python
-
+class Solution:
+    def minimizeStringValue(self, s: str) -> str:
+        cnt = Counter(s)
+        pq = [(cnt[c], c) for c in ascii_lowercase]
+        heapify(pq)
+        t = []
+        for _ in range(s.count("?")):
+            v, c = pq[0]
+            t.append(c)
+            heapreplace(pq, (v + 1, c))
+        t.sort()
+        cs = list(s)
+        j = 0
+        for i, c in enumerate(s):
+            if c == "?":
+                cs[i] = t[j]
+                j += 1
+        return "".join(cs)
 ```
 
 ```java
-
+class Solution {
+    public String minimizeStringValue(String s) {
+        int[] cnt = new int[26];
+        int n = s.length();
+        int k = 0;
+        char[] cs = s.toCharArray();
+        for (char c : cs) {
+            if (c == '?') {
+                ++k;
+            } else {
+                ++cnt[c - 'a'];
+            }
+        }
+        PriorityQueue<int[]> pq
+            = new PriorityQueue<>((a, b) -> a[0] == b[0] ? a[1] - b[1] : a[0] - b[0]);
+        for (int i = 0; i < 26; ++i) {
+            pq.offer(new int[] {cnt[i], i});
+        }
+        int[] t = new int[k];
+        for (int j = 0; j < k; ++j) {
+            int[] p = pq.poll();
+            t[j] = p[1];
+            pq.offer(new int[] {p[0] + 1, p[1]});
+        }
+        Arrays.sort(t);
+
+        for (int i = 0, j = 0; i < n; ++i) {
+            if (cs[i] == '?') {
+                cs[i] = (char) (t[j++] + 'a');
+            }
+        }
+        return new String(cs);
+    }
+}
 ```
 
 ```cpp
-
+class Solution {
+public:
+    string minimizeStringValue(string s) {
+        int cnt[26]{};
+        int k = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                ++k;
+            } else {
+                ++cnt[c - 'a'];
+            }
+        }
+        priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
+        for (int i = 0; i < 26; ++i) {
+            pq.push({cnt[i], i});
+        }
+        vector<int> t(k);
+        for (int i = 0; i < k; ++i) {
+            auto [v, c] = pq.top();
+            pq.pop();
+            t[i] = c;
+            pq.push({v + 1, c});
+        }
+        sort(t.begin(), t.end());
+        int j = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                c = t[j++] + 'a';
+            }
+        }
+        return s;
+    }
+};
 ```
 
 ```go
-
+func minimizeStringValue(s string) string {
+	cnt := [26]int{}
+	k := 0
+	for _, c := range s {
+		if c == '?' {
+			k++
+		} else {
+			cnt[c-'a']++
+		}
+	}
+	pq := hp{}
+	for i, c := range cnt {
+		heap.Push(&pq, pair{c, i})
+	}
+	t := make([]int, k)
+	for i := 0; i < k; i++ {
+		p := heap.Pop(&pq).(pair)
+		t[i] = p.c
+		p.v++
+		heap.Push(&pq, p)
+	}
+	sort.Ints(t)
+	cs := []byte(s)
+	j := 0
+	for i, c := range cs {
+		if c == '?' {
+			cs[i] = byte(t[j] + 'a')
+			j++
+		}
+	}
+	return string(cs)
+}
+
+type pair struct{ v, c int }
+type hp []pair
+
+func (h hp) Len() int           { return len(h) }
+func (h hp) Less(i, j int) bool { return h[i].v < h[j].v || h[i].v == h[j].v && h[i].c < h[j].c }
+func (h hp) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+func (h *hp) Push(v any)        { *h = append(*h, v.(pair)) }
+func (h *hp) Pop() any          { a := *h; v := a[len(a)-1]; *h = a[:len(a)-1]; return v }
 ```
 
 <!-- tabs:end -->
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.cpp b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.cpp
@@ -0,0 +1,33 @@
+class Solution {
+public:
+    string minimizeStringValue(string s) {
+        int cnt[26]{};
+        int k = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                ++k;
+            } else {
+                ++cnt[c - 'a'];
+            }
+        }
+        priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
+        for (int i = 0; i < 26; ++i) {
+            pq.push({cnt[i], i});
+        }
+        vector<int> t(k);
+        for (int i = 0; i < k; ++i) {
+            auto [v, c] = pq.top();
+            pq.pop();
+            t[i] = c;
+            pq.push({v + 1, c});
+        }
+        sort(t.begin(), t.end());
+        int j = 0;
+        for (char& c : s) {
+            if (c == '?') {
+                c = t[j++] + 'a';
+            }
+        }
+        return s;
+    }
+};
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.go b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.go
@@ -0,0 +1,41 @@
+func minimizeStringValue(s string) string {
+	cnt := [26]int{}
+	k := 0
+	for _, c := range s {
+		if c == '?' {
+			k++
+		} else {
+			cnt[c-'a']++
+		}
+	}
+	pq := hp{}
+	for i, c := range cnt {
+		heap.Push(&pq, pair{c, i})
+	}
+	t := make([]int, k)
+	for i := 0; i < k; i++ {
+		p := heap.Pop(&pq).(pair)
+		t[i] = p.c
+		p.v++
+		heap.Push(&pq, p)
+	}
+	sort.Ints(t)
+	cs := []byte(s)
+	j := 0
+	for i, c := range cs {
+		if c == '?' {
+			cs[i] = byte(t[j] + 'a')
+			j++
+		}
+	}
+	return string(cs)
+}
+
+type pair struct{ v, c int }
+type hp []pair
+
+func (h hp) Len() int           { return len(h) }
+func (h hp) Less(i, j int) bool { return h[i].v < h[j].v || h[i].v == h[j].v && h[i].c < h[j].c }
+func (h hp) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+func (h *hp) Push(v any)        { *h = append(*h, v.(pair)) }
+func (h *hp) Pop() any          { a := *h; v := a[len(a)-1]; *h = a[:len(a)-1]; return v }
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.java b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.java
diff --git a/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.py b/solution/3000-3099/3081.Replace Question Marks in String to Minimize Its Value/Solution.py
