feat: add cpp solutions to lcof problems: No.41,43,45

Author: maolonglong

lcof/面试题41. 数据流中的中位数/README.md

@@ -165,6 +165,43 @@ MedianFinder.prototype.findMedian = function () {
 };
 ```
 
+### **C++**
+
+```cpp
+class MedianFinder {
+public:
+    /** initialize your data structure here. */
+    MedianFinder() {
+    }
+
+    void addNum(int num) {
+        if (maxHeap.size() == minHeap.size()) {
+            maxHeap.push(num);
+            int temp = maxHeap.top();
+            maxHeap.pop();
+            minHeap.push(temp);
+        } else {
+            minHeap.push(num);
+            int temp = minHeap.top();
+            minHeap.pop();
+            maxHeap.push(temp);
+        }
+    }
+
+    double findMedian() {
+        if (maxHeap.size() == minHeap.size()) {
+            return (maxHeap.top() + minHeap.top()) / 2.0;
+        }
+        return minHeap.top();
+    }
+
+private:
+    priority_queue<int> maxHeap;
+    priority_queue<int, vector<int>, greater<int>> minHeap;
+
+};
+```
+
 ### **...**
 
 ```

lcof/面试题41. 数据流中的中位数/Solution.cpp

@@ -0,0 +1,32 @@
+class MedianFinder {
+public:
+    /** initialize your data structure here. */
+    MedianFinder() {
+    }
+
+    void addNum(int num) {
+        if (maxHeap.size() == minHeap.size()) {
+            maxHeap.push(num);
+            int temp = maxHeap.top();
+            maxHeap.pop();
+            minHeap.push(temp);
+        } else {
+            minHeap.push(num);
+            int temp = minHeap.top();
+            minHeap.pop();
+            maxHeap.push(temp);
+        }
+    }
+
+    double findMedian() {
+        if (maxHeap.size() == minHeap.size()) {
+            return (maxHeap.top() + minHeap.top()) / 2.0;
+        }
+        return minHeap.top();
+    }
+
+private:
+    priority_queue<int> maxHeap;
+    priority_queue<int, vector<int>, greater<int>> minHeap;
+
+};

lcof/面试题43. 1～n整数中1出现的次数/README.md

@@ -119,6 +119,35 @@ var countDigitOne = function (n) {
 };
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    int countDigitOne(int n) {
+        long long digit = 1;
+        int count = 0;
+        int high = n / 10;
+        int cur = n % 10;
+        int low = 0;
+        while (high != 0 || cur != 0) {
+            if (cur == 0) {
+                count += high * digit;
+            } else if (cur == 1) {
+                count += high * digit + low + 1;
+            } else {
+                count += (high + 1) * digit;
+            }
+            low += cur * digit;
+            cur = high % 10;
+            high /= 10;
+            digit *= 10;
+        }
+        return count;
+    }
+};
+```
+
 ### **...**
 
 ```

lcof/面试题43. 1～n整数中1出现的次数/Solution.cpp

@@ -0,0 +1,24 @@
+class Solution {
+public:
+    int countDigitOne(int n) {
+        long long digit = 1;
+        int count = 0;
+        int high = n / 10;
+        int cur = n % 10;
+        int low = 0;
+        while (high != 0 || cur != 0) {
+            if (cur == 0) {
+                count += high * digit;
+            } else if (cur == 1) {
+                count += high * digit + low + 1;
+            } else {
+                count += (high + 1) * digit;
+            }
+            low += cur * digit;
+            cur = high % 10;
+            high /= 10;
+            digit *= 10;
+        }
+        return count;
+    }
+};

lcof/面试题45. 把数组排成最小的数/README.md

@@ -93,6 +93,29 @@ var minNumber = function (nums) {
 };
 ```
 
+### **C++**
+
+```cpp
+class Solution {
+public:
+    string minNumber(vector<int>& nums) {
+        int n = nums.size();
+        vector<string> strs(n);
+        for (int i = 0; i < n; ++i) {
+            strs[i] = to_string(nums[i]);
+        }
+        sort(strs.begin(), strs.end(), [](const string& s1, const string& s2) {
+            return s1 + s2 < s2 + s1;
+        });
+        string ans;
+        for (int i = 0; i < n; ++i) {
+            ans += strs[i];
+        }
+        return ans;
+    }
+};
+```
+
 ### **...**
 
 ```

lcof/面试题45. 把数组排成最小的数/Solution.cpp

@@ -0,0 +1,18 @@
+class Solution {
+public:
+    string minNumber(vector<int>& nums) {
+        int n = nums.size();
+        vector<string> strs(n);
+        for (int i = 0; i < n; ++i) {
+            strs[i] = to_string(nums[i]);
+        }
+        sort(strs.begin(), strs.end(), [](const string& s1, const string& s2) {
+            return s1 + s2 < s2 + s1;
+        });
+        string ans;
+        for (int i = 0; i < n; ++i) {
+            ans += strs[i];
+        }
+        return ans;
+    }
+};